75 research outputs found

    A Novel Dimeric Inhibitor Targeting Beta2GPI in Beta2GPI/Antibody Complexes Implicated in Antiphospholipid Syndrome

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    Background: b2GPI is a major antigen for autoantibodies associated with antiphospholipid syndrome (APS), an autoimmune disease characterized by thrombosis and recurrent pregnancy loss. Only the dimeric form of b2GPI generated by anti-b2GPI antibodies is pathologically important, in contrast to monomeric b2GPI which is abundant in plasma. Principal Findings: We created a dimeric inhibitor, A1-A1, to selectively target b2GPI in b2GPI/antibody complexes. To make this inhibitor, we isolated the first ligand-binding module from ApoER2 (A1) and connected two A1 modules with a flexible linker. A1-A1 interferes with two pathologically important interactions in APS, the binding of b2GPI/antibody complexes with anionic phospholipids and ApoER2. We compared the efficiency of A1-A1 to monomeric A1 for inhibition of the binding of b2GPI/antibody complexes to anionic phospholipids. We tested the inhibition of b2GPI present in human serum, b2GPI purified from human plasma and the individual domain V of b2GPI. We demonstrated that when b2GPI/antibody complexes are formed, A1-A1 is much more effective than A1 in inhibition of the binding of b2GPI to cardiolipin, regardless of the source of b2GPI. Similarly, A1-A1 strongly inhibits the binding of dimerized domain V of b2GPI to cardiolipin compared to the monomeric A1 inhibitor. In the absence of anti-b2GPI antibodies, both A1-A1 and A1 only weakly inhibit the binding of pathologically inactive monomeric b2GPI to cardiolipin. Conclusions: Our results suggest that the approach of using a dimeric inhibitor to block b2GPI in the pathologica

    FLAIR* to visualize veins in white matter lesions: A new tool for the diagnosis of multiple sclerosis?

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    Royal College of Radiologists (pump priming grant to RJPS). MEM is partly funded (20%) by the Barts and the London National Institute for Health Research Cardiovascular Biomedical Research Unit. Additional study support provided by the Intramural Research Program of the National Institute of Neurological Disorders and Stroke, USA

    Frequent sputum production is associated with disturbed night's rest and impaired sleep quality in patients with COPD

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    Purpose In this study, we measured night's rest parameters measured with an accelerometer and sleep quality in mild to very severe patients with COPD. Furthermore, our aim was to investigate the association between night's rest parameters and clinical variables and the association between sleep quality and quality of life or health status. Methods Mild to very severe COPD patients were recruited from general practitioners and outpatient clinics of general hospitals to participate in a cross-sectional study on physical activity in patients with COPD. A total of 103 patients (mean age 65 years, 67 % male) wore the accelerometer during night's rest for at least four nights and were included in the analyses. Results No significant associations were found between objectively measured body movements during night's rest or subjective sleep quality and lung function, dyspnoea severity, body composition and physical activity during the day. Patients with frequent sputum production during the day had a higher number of sitting transitions during the night (5.3 vs 4.3 sitting transitions) and more frequently got out of bed compared to patients who hardly ever produced sputum during the day (1.0 vs 0.8 times per night). Furthermore, these patients also reported worse sleep quality (Pittsburgh sleep quality index (PSQI) score 4 vs 3). Conclusions Our results indicate that objectively measured body movements during night's rest like body postures and transitions are not related to sleep quality in patients with COPD. We did find an association between frequent sputum production and disturbances during night's rest and sleep quality. Future studies should investigate whether the treatment of mucus hypersecretion leads to improved night's rest

    Prevalence of superficial siderosis following singular, acute aneurysmal subarachnoid hemorrhage.

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    Superficial siderosis is presumably a consequence of recurrent bleeding into the subarachnoid space. The objective of this study was to assess the prevalence of superficial siderosis after singular, aneurysmal subarachnoid hemorrhage (SAH) in the long term.We retrospectively identified all patients who presented with a singular, acute, aneurysmal SAH at our institution between 2010 and 2013 and in whom a magnetic resonance imaging (MRI) including T2*-weighted imaging was available at least 4 months after the acute bleeding event. MRI scans were judged concerning the presence and distribution of superficial siderosis. Influence of clinical data, Fisher grade, localization, and cause of SAH as well as the impact of neurosurgical interventions on the occurrence of superficial siderosis was tested.Seventy-two patients with a total of 117 MRIs were included. Mean delay between SAH and the last available MRI was 47.4 months (range 4-129). SAH was Fisher grade 1 in 2 cases, 2 in 4 cases, 3 in 10 cases, and 4 in 56 cases. Superficial siderosis was detected in 39 patients (54.2%). In all patients with more than one MRI scan, localization and distribution of superficial siderosis did not change over time. Older age (p = 0.02) and higher degree of SAH (p = 0.03) were significantly associated with the development of superficial siderosis.Superficial siderosis develops in approximately half of patients after singular, aneurysmal SAH and might be more common in patients with an older age and a greater amount of blood. However, additional factors must play a role in whether a patient is prone to develop superficial siderosis or not

    Diffusion tensor imaging of the trigeminal nerve in patients with trigeminal neuralgia due to multiple sclerosis.

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    Neurovascular compression (NVC) is the most common cause of trigeminal neuralgia (TN), leading to microstructural changes in the affected nerve detectable using diffusion tensor imaging (DTI). But TN may also emerge as a symptom of multiple sclerosis (MS). The aim of this study was to evaluate if patients with MS-related TN feature the same DTI characteristics as patients with TN caused by NVC.Twelve patients with MS-related TN, 12 age-matched patients with NVC-related TN, and 12 healthy controls were included. Using 3T-DTI, mean fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated for each affected and contralateral trigeminal nerve in patients with MS and NVC-related TN as well as healthy controls. Furthermore, presence of NVC was evaluated for patients with TN.There was no significant difference concerning FA or ADC when comparing the affected and the non-affected sides in patients with MS. FA was significantly lower and ADC higher in patients with MS on the TN affected as well as on the non-affected side compared to the non-affected side of patients with idiopathic TN or healthy controls. Likewise, FA was significantly lower on the affected side compared to the non-affected side in patients with idiopathic TN or healthy controls. NVC was evident in 41.7/0% on the affected/contralateral side in MS patients and 100/8% in the patients with NVC-related TN.In patients with MS-related TN, DTI reveals microstructural changes within the trigeminal nerve not only on the affected side but also on the clinically non-affected side

    Presence of a central vein within white matter lesions on susceptibility weighted imaging: a specific finding for multiple sclerosis?

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    Susceptibility weighted imaging depicts the perivenous extent of multiple sclerosis white matter lesions (MS-WML) in vivo by directly visualizing their centrally running vein. The aim of this study was to investigate the specificity of this finding for MS.Fifteen patients with MS and 15 patients with microangiopathic white matter lesions (mWML) underwent 3T MRI, including a fluid-attenuated inversion recovery sequence (FLAIR) and a susceptibility weighted angiography (SWAN). All WMLs were identified on FLAIR and assigned to one of the following localizations: supratentorial peripheral, supratentorial periventricular, or infratentorial. Subsequently, the presence of a central vein within these lesions was assessed on SWAN.A total of 711 MS-WMLs and 1,119 m-WMLs were identified on FLAIR, all of which could also be visualized on SWAN. A central vein was detectable in 80% of the MS-WMLs and in 78% of the m-WMLs (in 73% and 76% of the peripheral, in 92% and 94% of the periventricular, and in 71% and 75% of the infratentorial MS-WMLs and m-WMLs, respectively). With regard to the supratentorial peripheral lesions, significantly more m-WMLs showed a central vein compared to the MS-WMLs. For the other localizations, there was no significant difference between the groups with regard to the percentage of lesions with central vein.Our results indicate that the detection of a central vein within a WML should not be considered a specific finding for MS; it is also found in WMLs of other etiologies

    Evaluation of the supraaortic arteries using non-contrast-enhanced Velocity MR angiography "Inhance".

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    The aim of this study was to compare the recently developed phase contrast-based Inhance 3D Velocity magnetic resonance angiography technique (Inhance) to the contrast-enhanced standard method (CE-MRA) in the evaluation of the supraaortic arteries.Inhance and CE-MRA were performed in ten consecutive patients with a suspected pathology of the supraaortic arteries on a 3-T MR scanner. Two neuroradiologists evaluated in consensus both sequences regarding the visualisation of the supraaortic arteries and their segments on a five-point score. Diagnostic certainty regarding the overall presence of a vascular pathology was rated on the same five-point score.On CE-MRA as well as on Inhance, a vascular pathology of the supraaortic arteries was detected in seven patients. There was no statistically significant difference in the overall diagnostic certainty regarding the presence or absence of pathologic findings for CE-MRA compared to Inhance. Furthermore, no statistically significant difference was found with regard to visualisation of the distal cervical and intracranial arterial segments, while CE-MRA was superior to Inhance in the visualisation of the origins of the cervical vessels from the aortic arch.Non-contrast Inhance proved useful in the evaluation of the supraaortic arteries with limited assessment of the proximal supraaortic branches. Hence, this technique features a valuable alternative to CE-MRA in the visualisation of the supraaortic arteries, particularly in patients with renal insufficiency

    Spectrum and Prevalence of Pathological Intracranial Magnetic Resonance Imaging Findings in Acute Bacterial Meningitis.

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    Aim of this study was to determine the spectrum and prevalence of pathological intracranial magnetic resonance imaging (MRI) findings in patients with acute bacterial meningitis.We retrospectively identified all consecutive patients with cerebral spinal fluid proven bacterial meningitis who presented at our neurology department between 2007 and 2012. Pathogenic agents and clinical symptoms were noted. MR-examinations were evaluated regarding presence and localization of pathological signal alterations in the different sequences by two neuroradiologists in consensus.A total of 136 patients with purulent bacterial meningitis were identified. In 114 cases the bacterial pathogen agent was proven and in 75 patients an MRI was available. In 62 of the 75 (82.7 %) patients meningitis-associated pathologic imaging findings were evident on MRI. Overall, intraventricular signal alterations, i.e., signs of pyogenic ventriculitis, were present in 41 cases (54.7 %), while sulcal signal changes were found in 22 cases (29.3 %). Intraparenchymatous signal alterations affected the cortex in 15 cases (20 %), and the white matter in 20 patients (26.7 %). The diffusion-weighted imaging and fluid attenuated inversion recovery sequences were most sensitive in the detection of these changes and showed any pathologic findings in 67.6 and 79.6 %, respectively. Patients with streptococcal meningitis showed significantly more often (n = 29 of 34, 85.3 %) intraventricular and/or sulcal diffusion restrictions than patients with meningitis caused by other agents (n = 12 of 37, 32.4 %) (p< 0.0001).Pathological MR findings are frequently found in patients with acute bacterial meningitis. Intraventricular diffusion restrictions, i.e., signs of pyogenic ventriculitis, are more often found in patients with streptococcal, especially pneumococcal, infection
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