The role of the capsid protein in Semliki Forest virus assembly

Enveloped viruses, like the Alphaviruses, encapsidate their genomes into a nucleocapsid (NC) or core structure which is surrounded by a lipid bilayer (envelope) with spike proteins. The alphavirus Semliki Forest virus (SFV), is an RNA virus with a genomic 42 S RNA of positive polarity. SFV aquires its envelope by budding at the plasmamembrane (PM) where interactions between spike protein complexes in the membrane and preformed NCs in the cytoplasm are thought to drive formation of new virus particles. In addition to these spike-C interactions, lateral (horisontal) spikespike interactions on the external surface of the lipid bilayer have been implicated. During virus entry, NCs from the incoming virus are delivered in the cytoplasm and the RNA uncoated by an as yet poorly defined mechanism. The C protein of SFV consists of two domains: an N-terminal domain, which is thought to mediate RNA binding and a chymotrypsin-like C-terminal domain which is suggested to bind to the spike complexes. The N-terminal domain contain three regions (I-III) with high concentrations of residues with positively charged side chains and two other conserved regions with many uncharged residues. To this end I have engineered mutants with various deletions in the N-terminus of C. I have tested the role of these regions in RNA encapsidation, NC assembly, budding and RNA uncoating. I found that the bulk of the positively charged residues were needed to condense the viral RNA into NCs. The positive charges will probably bind to negatively charged phosphate groups in the RNA and thus pack the RNA chain. When the number of positive charges was decreased under a certain treshold the genomic 42 S RNA could not be encapsidated but instead, the subgenomic 26 S RNA was encapsidated. The conserved, uncharged regions were necessary for NC assembly and seemed to be involved in C-C interactions. A deletion, which removed both uncharged regions and the charged regions 11 and III from the C protein resulted in a virus that had lost its ability, to preform NCs in cytoplasm. Surprisingly, this virus could still form enveloped virus particles with correct icosahedral symmetry. This demonstrates that the membrane proteins have the capacity to direct icosahedral virus assembly. I also tested the generality of an RNA encasidation signal-binding activity which is proposed to reside in the second conserved region with many uncharged residues. My results showed that this region is not essential for genome encapsidation in SFV although this seems to be the case in the related Sindbis virus. Finally, I could show that the same conserved region is not essential for genome uncoating as was earlier suggested by others for both SFV and Sindbis virus

Initial Low Levels of Suicidal Ideation Still Improve After Cognitive Behavioral Therapy for Insomnia in Regular Psychiatric Care

Insomnia disorder is highly prevalent, and has been identified as a risk factor for many psychiatric problems, including depression, suicide ideation and suicide death. Previous studies have found that cognitive behavioral therapy for insomnia (CBT-I) reduce depression and suicidal ideation in samples with high levels of suicidal ideation. This study aims to investigate associations of CBT-I with suicidal ideation in a sample of 522 patients primarily seeking internet-delivered treatment for insomnia in regular psychiatric care. The sample had high pretreatment insomnia severity levels and a relatively high level of comorbid depression symptoms. Suicidal ideation levels were relatively low pretreatment but still improved significantly after CBT-I. Contrary to previous findings, the strongest predictor of changes in suicidal ideation were improvements in depressive symptoms, rather than improvements in insomnia. We conclude that suicidal ideation may not be a major problem in these patients primarily seeking treatment for insomnia, despite comorbid depressive symptoms, but that suicidal ideation still improves following CBT-i. Considering the increased risk for patients with untreated insomnia to develop depression, this finding is of interest for prevention of suicidal ideation.</jats:p

Psychological Treatment of Comorbid Insomnia and Depression : A Double-Blind Randomized Placebo-Controlled Trial

Introduction: Insomnia and depression are highly prevalent disorders and commonly occur together. Cognitive behavioral therapy for insomnia, CBT-I, has been shown to be effective in treating insomnia and also comorbid depression. However, it is unclear whether effects of CBT-I on depression are specific or nonspecific. Also, depressive symptoms often remain too high after CBT-I, indicating a need for improved treatments. The objective was to determine whether combining CBT-I with CBT for depression, without increasing treatment length, reduces both insomnia and depression more than CBT for depression with a placebo insomnia intervention. Methods: A 12-week double-blind randomized controlled trial with a 6-month follow-up in a psychiatric setting using therapist-guided internet-delivered treatments was conducted. Patients (N = 126) were diagnosed with insomnia disorder and major depression by physicians. Primary outcome measures were as follows: self-rating scales Insomnia Severity Index (ISI) and Montgomery-angstrom sberg Depression Rating Scale (MADRS-S). Results: The combined treatment showed specific effects on insomnia severity over the control treatment (p = 0.007) but was not more effective in reducing depression severity. Within-group effects (Cohen's d) at post and at 6 months were as follows: ISI 1.40 and 1.42 (combined treatment), 0.95 and 1.00 (control); MADRS-S 0.97 and 1.12 (combined), 0.88 and 0.89 (control). Conclusions: CBT-I shows large specific effects on insomnia severity and is superior to control in this regard. Both treatments had similar effects on depression severity, i.e., combining CBT-I with CBT for depression did not enhance outcomes on depression compared to control. We suggest CBT-I should always be offered to patients with insomnia and depression comorbidity, possibly as the first-hand choice. Combining it with a psychological treatment for depression could be too burdening and may not be beneficial

The influence of cardiac triggering time and an optimization strategy for improved cardiac MR spectroscopy

To study how cardiac motion affects the spectral quality in cardiac MR spectroscopy and to establish an optimization strategy for the cardiac triggering time for improved quality and success rate of cardiac MRS.Water spectra were acquired while the cardiac triggering time was varied over the cardiac cycle, and five different spectral quality parameters were studied (frequency, phase, linewidth, amplitude and noise). Furthermore, three different optimization strategies for the cardiac triggering time were tested, and finally, a comparison was made between water suppressed lipid spectra acquired in systole and diastole.The cardiac triggering time had a high impact on the spectral quality, especially on the mean signal amplitude and the standard deviation of the signal amplitude, phase and linewidth. Generally, the highest spectral quality was observed for spectra acquired in mid to end systole, at approximately 23% of the cardiac cycle. The exact optimal triggering time differed between subjects and needed to be individually optimized. To optimize the triggering time with our proposed MRS-method gave in average 13% higher signal than when the triggering time was determined through imaging. Lipid spectra acquired in systole demonstrated higher quality with improved SNR compared with acquisitions made in diastole.This study shows that the spectral quality in cardiac MRS is strongly dependent on the cardiac triggering time, and that the spectral quality as well as the repeatability between acquisitions is greatly improved when the cardiac triggering time is individually optimized in mid to end systole using MRS

Development of a very brief scale for detecting and measuring panic disorder using two items from the Panic Disorder Severity Scale-Self Report

Objective: To minimize the burden in detecting and monitoring Panic Disorder and Agoraphobia by developing a very brief scale with selected items from the Panic Disorder Severity Scale-Self Report (PDSS-SR), and to investigate the proposed scale's psychometric properties in a comorbid sample. Methods: A sample of 5103 patients from the Internet Psychiatry Clinic in Sweden, diagnosed and treated with Internet-based cognitive behavioral therapy for panic disorder (n = 1390), social anxiety disorder (n = 1313) or depression (n = 2400), responded to the PDSS-SR. Six criteria related to factor structure, sensitivity to change and clinical representativeness were used to select items. Psychometric analyses for the selected very brief scale were performed. Results: Items 2 (distress during panic attacks) and 4 (agoraphobic avoidance), were selected to create the very brief PDSS-SR version. Correlations with the full scale were high at screening, pre and post, and for change (0.87-0.93). Categorical Omega was omega(c) = 0.74. With a cut-off of 3 points, the scale could detect panic disorder in a psychiatric sample with a sensitivity of 85% and a specificity of 66%. Limitations: Limitations include lack of healthy controls and lack of blinding on secondary outcome measures. Conclusion: The proposed 2-item PDSS-SR version is a good candidate for a very brief panic disorder questionnaire, both for detecting cases and for measuring change. This is especially useful in clinical settings when measuring more than one condition at a time.</p

Proof of Concept for an Adaptive Treatment Strategy to Prevent Failures in Internet-Delivered CBT : A Single-Blind Randomized Clinical Trial With Insomnia Patients

Objective: This study aimed to demonstrate proof of concept for an adaptive treatment strategy in Internet-delivered cognitive-behavioral therapy (ICBT), where risk of treatment failure is assessed early in treatment and treatment for at-risk patients is adapted to prevent treatment failure. Methods: A semiautomated algorithm assessed risk of treatment failure early in treatment in 251 patients undergoing ICBT for insomnia with therapist guidance. At-risk patients were randomly assigned to continue standard ICBT or to receive adapted ICBT. The primary outcome was self-rated insomnia symptoms using the Insomnia Severity Index in a linear mixed-effects model. The main secondary outcome was treatment failure (having neither responded nor remitted at the posttreatment assessment). Results: A total of 102 patients were classified as at risk and randomly assigned to receive adapted ICBT (N=51) or standard ICBT (N=51); 149 patients were classified as not at risk. Patients not at risk had significantly greater score reductions on the Insomnia Severity Index than at-risk patients given standard ICBT. Adapted ICBT for at-risk patients was significantly more successful in reducing symptoms compared with standard ICBT, and it decreased the risk of failing treatment (odds ratio= 0.33). At-risk patients receiving adapted ICBT were not more likely to experience treatment failure than those not at risk (odds ratio= 0.51), though they were less likely to experience remission. Adapted treatment required, on average, 14 more minutes of therapist-patient time per remaining week. Conclusions: An adaptive treatment strategy can increase treatment effects for at-risk patients and reduce the number of failed treatments. Future studies should improve accuracy in classification algorithms and identify key factors that boost the effect of adapted treatments.</p