We show that the Cuntz splice induces stably isomorphic graph
C
∗
-algebras. This result is a key step towards the recent complete classification of unital graph
C
∗
-algebras both with respect to
K
...-theoretical classification and with respect to geometrical classification in terms of an equivalence relation on the underlying graphs.
Objectives
The traditional view that multiple sclerosis (MS) is an autoimmune disease has recently been challenged by the claim that MS is caused by chronic cerebrospinal venous insufficiency ...(CCSVI). Although several studies have questioned this vascular theory, the CCSVI controversy is still ongoing. Our aim was to assess the prevalence of CCSVI in Danish MS patients using sonography and compare these findings with MRI measures of venous flow and morphology.
Methods
We investigated cervical and cerebral veins in 24 patients with relapsing‐remitting MS (RRMS) and 15 healthy controls, using extracranial high‐resolution ultrasound colour Doppler (US‐CD) and transcranial colour Doppler sonography (TCDS), as well as magnetic resonance imaging (MRI) and phase‐contrast MR blood flow measurements (PC‐MR) of the cervical veins.
Results
US‐CD could not identify the left internal jugular vein (IJV) in one MS patient, other ultrasound examinations were normal in patients with MS. There was no difference in mean cross‐sectional area of the IJV in MS patients compared with controls. Only one patient with MS and two healthy controls fulfilled one CCSVI criterion, and none fulfilled more than one CCSVI criterion. MR venography showed insignificant IJV stenosis (1–49%) in two patients with MS, whereas 50–69% IJV stenosis was detected in two healthy controls. There was no difference in PC‐MR measurements of mean IJV blood flow between patients with MS and controls.
Conclusion
Our results do not corroborate the presence of vascular pathology in RRMS and we found no evidence supporting the CCSVI hypothesis.
•High serum NfL were associated with increasing MD and decreasing FA in NAWM.•High serum GFAP were independently associated with decreasing MD in NAWM.•High serum GFAP were associated with decreasing ...MD and increasing FA values in CGM.
The potential of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) as biomarkers of disease activity and severity in progressive forms of multiple sclerosis (MS) is unclear.
To investigate the relationship between serum concentrations of NfL, GFAP, and magnetic resonance imaging (MRI) in progressive MS.
Serum concentrations of NfL and GFAP were measured in 32 healthy controls and 32 patients with progressive MS from whom clinical and MRI data including diffusion tensor imaging (DTI) were obtained during three years of follow-up.
Serum concentrations of NfL and GFAP at follow-up were higher in progressive MS patients than in healthy controls and serum NfL correlated with the EDSS score. Decreasing fractional anisotropy (FA) in normal-appearing white matter (NAWM) correlated with worsening EDSS scores and higher serum NfL. Higher serum NfL and increasing T2 lesion volume correlated with worsening paced autitory serial addition test scores. In multivariable regression analyses with serum GFAP and NfL as independent factors and DTI measures of NAWM as dependent factors, we showed that high serum NfL at follow-up was independently associated with decreasing FA and increasing MD in NAWM. Moreover, we found that high serum GFAP was independently associated with decreasing MD in NAWM and with decreasing MD and increasing FA in cortical gray matter.
Serum concentrations of NfL and GFAP are increased in progressive MS and are associated with distinct microstructural changes in NAWM and CGM.
Background
Gender appears to play a role in incidence and disease course of multiple sclerosis (MS).
Objective
The objective was to determine whether male and female patients with MS respond ...differently to interferon‐beta treatment in terms of reduction in relapse rates.
Methods
We included all 2033 patients with relapsing–remitting MS who started treatment with interferon‐beta from 1996 to 2003, identified from the Danish Multiple Sclerosis Treatment Register. We defined neutralizing antibody (NAb)‐positive and NAb‐negative periods in the single patient by the results of the NAb tests. Patients served as their own controls, and relapse rates were compared between NAb‐negative and NAb‐positive periods.
Results
NAbs significantly abrogated the interferon‐beta treatment efficacy in both genders. The all‐over women:men relapse rate ratio irrespective of NAb status was 1.47 (95%CI; 1.28–1.68). In a generalized linear Poisson models analysis with relapse counts as response variable, the main effects NAbs, sex, age at treatment start and number of relapses in 2 years before treatment start were strongly significant, but the effect of NAbs on relapse rates did not differ significantly between men and women.
Conclusion
As NAbs influenced the on‐treatment relapse rates strongly in both sexes but without statistical significant difference, there is no indication of different effects of interferon‐beta in men or women.
Background: Glatiramer acetate (GA) treatment suppresses disease activity in multiple sclerosis (MS). The immunological response to treatment may differ in patients who are stable on GA therapy and ...patients with breakthrough disease activity, but the results of previous studies are inconsistent.
Objectives: We studied the immunological response to GA and its relationship with disease activity.
Methods: Anti-GA antibodies in plasma and the expression of genes encoding cytokines and T-cell-polarizing transcription factors in blood cells were analysed by flow cytometric bead array and polymerase chain reaction (PCR) analysis in 39 untreated and 29 GA-treated relapsing–remitting MS patients. Definition of breakthrough disease was based on the occurrence of relapses, disability progression, or gadolinium (Gd)-enhanced MRI.
Results: The expression of T helper type 1 (Th1) and Th17 cytokines and transcription factors was reduced during long-term treatment, but there was no relationship between the expression of cytokines and transcription factors and anti-GA antibodies. High expression of mRNA encoding GATA3 and lymphotoxin-β (LT-β) was associated with low disease activity in Gd-enhanced MRI studies. None of the variables studied were associated with clinical disease activity. GA treatment resulted in the development of IgG and IgG4 anti-GA antibodies during the first months of treatment, persisting during long-term treatment.
Conclusions: The observed relationship between the expression of mRNA encoding GATA3 and LT-β expression and MRI disease activity deserves further analysis in future studies. The development of anti-GA antibodies was observed in all patients treated with GA, but this was not related with measures of cellular immunity, clinical or MRI disease activity.
The magnitude of power fluctuations at large offshore wind farms has a significant impact on the control and management strategies of their power output. If focusing on the minute scale, it looks ...like different regimes yield different behaviours of the wind power output. The use of statistical regime-switching models is thus investigated. Regime-switching approaches relying on observable (i.e. based on recent wind power production) or non-observable (i.e. a hidden Markov chain) regime sequences are considered. The former approach is based on either self-exciting threshold autoregressive (SETAR) or smooth transition autoregressive (STAR) models, while Markov-switching autoregressive (MSAR) models comprise the kernel of the latter one. The particularities of these models are presented, as well as methods for the estimation of their parameters. The competing approaches are evaluated on a one-step ahead forecasting exercise with time-series of power production averaged at a 1, 5, and 10-min rate, at the Horns Rev and Nysted offshore wind farms in Denmark. For the former wind farm, the one-step ahead root mean square error (RMSE) is contained between 0.8% and 5% of installed capacity, while it goes from 0.6% to 3.9% of installed capacity for the case of Nysted. It is shown that the regime-switching approach based on MSAR models significantly outperforms those based on observable regime sequences. The reduction in one-step ahead RMSE ranges from 19% to 32% depending on the wind farm and time resolution considered. The presented results clearly demonstrate that the magnitude of fluctuations of offshore wind power cannot be considered as simply influenced by the generation level only.
Objective
To characterize the relationship between motor resting‐state connectivity of the dorsal pre‐motor cortex (PMd) and clinical disability in patients with multiple sclerosis (MS).
Materials ...and methods
A total of 27 patients with relapsing–remitting MS (RR‐MS) and 15 patients with secondary progressive MS (SP‐MS) underwent functional resting‐state magnetic resonance imaging. Clinical disability was assessed using the Expanded Disability Status Scale (EDSS). Independent component analysis was used to characterize motor resting‐state connectivity. Multiple regression analysis was performed in SPM8 between the individual expression of motor resting‐state connectivity in PMd and EDSS scores including age as covariate. Separate post hoc analyses were performed for patients with RR‐MS and SP‐MS.
Results
The EDSS scores ranged from 0 to 7 with a median score of 4.3. Motor resting‐state connectivity of left PMd showed a positive linear relation with clinical disability in patients with MS. This effect was stronger when considering the group of patients with RR‐MS alone, whereas patients with SP‐MS showed no increase in coupling strength between left PMd and the motor resting‐state network with increasing clinical disability. No significant relation between motor resting‐state connectivity of the right PMd and clinical disability was detected in MS.
Conclusions
The increase in functional coupling between left PMd and the motor resting‐state network with increasing clinical disability can be interpreted as adaptive reorganization of the motor system to maintain motor function, which appears to be limited to the relapsing–remitting stage of the disease.
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