Bacteria Hunt: Evaluating multi-paradigm BCI interaction

The multimodal, multi-paradigm brain-computer interfacing (BCI) game Bacteria Hunt was used to evaluate two aspects of BCI interaction in a gaming context. One goal was to examine the effect of feedback on the ability of the user to manipulate his mental state of relaxation. This was done by having one condition in which the subject played the game with real feedback, and another with sham feedback. The feedback did not seem to affect the game experience (such as sense of control and tension) or the objective indicators of relaxation, alpha activity and heart rate. The results are discussed with regard to clinical neurofeedback studies. The second goal was to look into possible interactions between the two BCI paradigms used in the game: steady-state visually-evoked potentials (SSVEP) as an indicator of concentration, and alpha activity as a measure of relaxation. SSVEP stimulation activates the cortex and can thus block the alpha rhythm. Despite this effect, subjects were able to keep their alpha power up, in compliance with the instructed relaxation task. In addition to the main goals, a new SSVEP detection algorithm was developed and evaluated

Non-response to rituximab therapy in rheumatoid arthritis is associated with incomplete disruption of the B cell receptor repertoire

Objective: To gain more insight into the dynamics of lymphocyte depletion and develop new predictors of clinical response to rituximab in rheumatoid arthritis (RA). Methods: RNA-based next-generation sequencing was used to analyse the B cell receptor (BCR) repertoire in peripheral blood and synovial tissue samples collected from 24 seropositive patients with RA treated with rituximab. Clonal expansion, mutation load and clonal overlap were assessed in samples collected before, at week 4 and at week 16 or 24 after treatment and correlated to the patients' clinical response. Results: After 4 weeks of rituximab-induced B cell depletion, the peripheral blood BCR repertoire of treated patients consisted of fewer, more dominant and more mutated BCR clones. No significant changes in the synovial tissue BCR repertoire were detected until week 16 post-treatment, when a reduced clonal overlap with baseline and an increased mutation load were observed. In patients who were non-responders at month 3 (n=5) using the European League Against Rheumatism response criteria, peripheral blood samples taken at week 4 after rituximab treatment showed more dominant clones compared with moderate responders (n=9) (median (IQR): 36 (27-52) vs 18 (16-26); p<0.01) and more clonal overlap with the baseline (median (IQR): 5% (2%-20%) vs 0% (0%-0%); p≤0.01). Conclusion: Significant changes in BCR clonality are observed in peripheral blood of patients 4 weeks after rituximab treatment, while changes in synovial tissue were observed at later time points. Incomplete depletion of the dominant baseline peripheral blood BCR repertoire in the first month of treatment might predict clinical non-response at 3 months

Functional Tissue Analysis Reveals Successful Cryopreservation of Human Osteoarthritic Synovium

<div><p>Osteoarthritis (OA) is a degenerative joint disease affecting cartilage and is the most common form of arthritis worldwide. One third of OA patients have severe synovitis and less than 10% have no evidence of synovitis. Moreover, synovitis is predictive for more severe disease progression. This offers a target for therapy but more research on the pathophysiological processes in the synovial tissue of these patients is needed. Functional studies performed with synovial tissue will be more approachable when this material, that becomes available by joint replacement surgery, can be stored for later use. We set out to determine the consequences of slow-freezing of human OA synovial tissue. Therefore, we validated a method that can be applied in every routine laboratory and performed a comparative study of five cryoprotective agent (CPA) solutions. To determine possible deleterious cryopreservation-thaw effects on viability, the synovial tissue architecture, metabolic activity, RNA quality, expression of cryopreservation associated stress genes, and expression of OA characteristic disease genes was studied. Furthermore, the biological activity of the cryopreserved tissue was determined by measuring cytokine secretion induced by the TLR ligands lipopolysaccharides and Pam3Cys. Compared to non frozen synovium, no difference in cell and tissue morphology could be identified in the conditions using the CS10, standard and CryoSFM CPA solution for cryopreservation. However, we observed significantly lower preservation of tissue morphology with the Biofreeze and CS2 media. The other viability assays showed trends in the same direction but were not sensitive enough to detect significant differences between conditions. In all assays tested a clearly lower viability was detected in the condition in which synovium was frozen without CPA solution. This detailed analysis showed that OA synovial tissue explants can be cryopreserved while maintaining the morphology, viability and phenotypical response after thawing, offering enhanced opportunities for human <i>in vitro</i> studies.</p></div

No effect of cryopreservation on RNA integrity in synovial explants.

<p>The RIN was determined in triplo of OA synovial tissue from four patients, 24 hours after thawing. Numbers indicate the number of biopsies of which the RIN could be successfully determined. Displayed is the mean +/- the SD. Statistical analysis was performed by one-way ANOVA, comparing the non-frozen control to the cryopreserved conditions.</p

No effect of cryopreservation on disease characteristic gene expression.

<p>Gene expression of <i>TIMP3</i> (A), <i>CCL18</i> (B) and <i>MMP9</i> (C) was determined after thawing and 24 hours culture of synovial biopsies of four patients. Per patient 3 biopsies were included in the analysis. Patient 6: green dots, patient 7: black dots, patient 8: dark blue dots, patient 4: light blue dots. Displayed is the mean +/- SD. Statistical analysis was performed by one-way ANOVA, comparing the non-frozen control to the cryopreserved conditions.</p

Analysis of cryopreservation-induced changes in disease- characteristic gene expression compared to non-frozen tissue in individual OA patients.

<p>Analysis of cryopreservation-induced changes in disease- characteristic gene expression compared to non-frozen tissue in individual OA patients.</p

Histological analysis of cryopreserved synovial explants.

<p>(A) Histological preservation was determined by assessing global histological parameters using an arbitrary score. Mean score is displayed. A significantly lower score was determined for the CS2, Biofreeze and without CPA condition. Blue dots: patient 1, black dots: patient 2, grey dots: patient 3. For statistical analysis, one-way ANOVA was performed, comparing the non frozen control to the cryopreserved conditions. *** p<0.001. Displayed is the mean. (B) Non frozen highly cellular synovium from patient 1. (C) Synovium of low cellularity cryopreserved with CryoSFM of patient 2 displaying an intact and smooth intimal lining layer (arrow), intact cells and blood vessels (*). (D) Synovium from patient 3 cryopreserved with CryoSFM, displaying mainly intimal lining hyperplasia (arrow), the lining is smooth and intact, cells and blood vessels (*) are intact. (E) Synovium of patient 2 cryopreserved using the Biofreeze medium, showing a disrupted intimal lining layer (arrow), a high number of disrupted cells and disrupted blood vessels (*). (F) Synovium of patient 1 frozen without protecting CPA solution showing almost complete disruption of cells.</p