Paraneoplastic pemphigus uncovers distinct clinical and biological phenotypes of western unicentric Castleman disease.

Unicentric Castleman disease (UCD) is a lymphoproliferative disease of unknown cause. Paraneoplastic pemphigus (PNP) is a major complication shown to be associated with a poor prognosis, with particular severity in patients with bronchiolitis obliterans (BO). This study describes the clinical and biological characteristics of UCD-PNP patients in a large Western cohort. A total of 148 patients diagnosed with UCD were identified, including 14 patients with a defined PNP. PNP was significantly associated with myasthenia gravis (MG) and FDC sarcoma during follow-up (FDCS). PNP was also significantly associated with reduced survival. These data, together with a multivariate analysis by principal components, led to the identification of UCD-PNP as a group at risk of MG, FDCS and death. PDGFRB sequencing performed on UCD lesions from six patients found the gain-of-function p.N666S variant in two. Interestingly, both patients had hyaline-vascular UCD subtype, were in the UCD-PNP subgroup and had FDCS. Sera from 25 UCD-PNP patients and 6 PNP patients without UCD were tested for PNP-associated autoantibodies. Sera from UCD-PNP patients had a strong reactivity against the N-terminal domain of recombinant periplakin (rPPL, 82%) and showed reactivity against at least two domains of rPPL. These features were not found in patients with UCD alone or in the PNP group without UCD. These data indicate that UCD-PNP patients belong to a subgroup sharing strong clinical and biological identity that might help to decipher the different dynamics of UCD natural history.

X-ray mirrors with sub-nanometre figure errors obtained by differential deposition of thin WSi2 films.

Differential deposition by DC magnetron sputtering was applied to correct for figure errors of X-ray mirrors to be deployed on low-emittance synchrotron beamlines. During the deposition process, the mirrors were moved in front of a beam-defining aperture and the required velocity profile was calculated using a deconvolution algorithm. The surface figure was characterized using conventional off-line visible-light metrology instrumentation (long trace profiler and Fizeau interferometer) before and after the deposition. WSi2 was revealed to be a promising candidate material since it conserves the initial substrate surface roughness and limits the film stress to acceptable levels. On a 300 mm-long flat Si mirror the average height errors were reduced by a factor of 20 down to 0.2 nm root mean square. This result shows the suitability of WSi2 for differential deposition. Potential promising applications include the upgrade of affordable, average-quality substrates to the standards of modern synchrotron beamlines.

Kidney Histopathology Can Predict Kidney Function in ANCA-Associated Vasculitides with Acute Kidney Injury Treated with Plasma Exchanges.

BACKGROUND: Data from the PEXIVAS trial challenged the role of plasma exchange (PLEX) in ANCA-associated vasculitides (AAV). We aimed to describe kidney biopsy from patients with AAV treated with PLEX, evaluate whether histopathologic findings could predict kidney function, and identify which patients would most benefit from PLEX. METHODS: We performed a multicenter, retrospective study on 188 patients with AAV and AKI treated with PLEX and 237 not treated with PLEX. The primary outcome was mortality or KRT at 12 months (M12). RESULTS: No significant benefit of PLEX for the primary outcome was found. To identify patients benefitting from PLEX, we developed a model predicting the average treatment effect of PLEX for an individual depending on covariables. Using the prediction model, 223 patients had a better predicted outcome with PLEX than without PLEX, and 177 of them had >5% increased predicted probability with PLEX compared with without PLEX of being alive and free from KRT at M12, which defined the PLEX-recommended group. Risk difference for death or KRT at M12 was significantly lower with PLEX in the PLEX-recommended group (-15.9%; 95% CI, -29.4 to -2.5) compared with the PLEX not recommended group (-4.8%; 95% CI, 14.9 to 5.3). Microscopic polyangiitis, MPO-ANCA, higher serum creatinine, crescentic and sclerotic classes, and higher Brix score were more frequent in the PLEX-recommended group. An easy to use score identified patients who would benefit from PLEX. The average treatment effect of PLEX for those with recommended treatment corresponded to an absolute risk reduction for death or KRT at M12 of 24.6%. CONCLUSIONS: PLEX was not associated with a better primary outcome in the whole study population, but we identified a subset of patients who could benefit from PLEX. However, these findings must be validated before utilized in clinical decision making.

X-ray mirror figure correction by differential deposition and off-line metrology.

The surface figure error of a hard X-ray mirror was improved by combining differential deposition and off-line metrology tools. Thin Cr layers were deposited on flat substrates by DC magnetron sputtering. The substrates were moved in front of a beam-defining aperture. The required velocity profile was calculated using a deconvolution algorithm. The Cr thickness profiles were measured directly using hard X-ray reflectivity data. The surface figure was characterized using conventional visible-light metrology instrumentation (long trace profiler) before and after the deposition. The method converges quickly, and after two iterations the mirror surface figure had improved by a factor of 7. The surface roughness evolves with increasing Cr thickness and deteriorates the quality of subsequent multilayer coatings. The mirror curvature can change upon coating, which complicates the interpretation of the surface metrology data. In this context, the role of layer stress is discussed. Potential improvements of the process are also proposed.

Long-term outcome of monoclonal (type 1) cryoglobulinemia.

The aim of this study is to investigate long-term outcome of symptomatic type 1 cryoglobulinemia (CG) and its determinants. Retrospective cohort study was conducted in two French University Hospitals. Patients with type 1 CG were identified using laboratory databases. Inclusion criterion was the presence of persistent symptoms of CG. Among 227 screened patients, 36 were included. Skin or vasomotor symptoms were the most frequent features (75%). Nephropathy and neuropathy occurred in 30% and 47% of cases, respectively. The underlying B cell disease (BCD) was a nonmalignant monoclonal gammopathy (NMMG) in 13 (36%) and a hematologic malignancy (HM) in 23 (64%; Waldenstrom macroglobulinemia (WM) in 12, low-grade non-Hodgkin lymphoma (NHL) in 6, multiple myeloma (MM) in 4, and chronic lymphocytic leukemia in 1 patient. Severe manifestations affected half the patients and were more frequent with IgG (82 vs. 30% (P = 0.006)). At last follow-up, 64% of patients had suffered no hematologic manifestation. Potent chemotherapeutic regimens were mainly used in HM. For patients with NMMG, WM, or NHL, fludarabine or rituximab-based regimens appeared to yield better responses. Five-year survival rate was 82%. In multivariate analysis, mortality was significantly higher in older patients (HR: 1.17 per year [95% CI: 1.06-1.28], P = 0.001) and those with nephropathy (HR: 8.9 [95% CI: 1.9-43], P = 0.006). Kidney disease, infections, Richter's transformation, and second malignancies were important sources of morbi-mortality. Despite its limitations, this series provide novel information regarding type 1 CG. Further studies are needed to improve its management. To date, therapeutic strategy should be tailored according to patient's characteristics (age, comorbidities, underlying BCD), and therapeutic target.

Fabrication of ultrashort sub-meter-radius x-ray mirrors using dynamic stencil deposition with figure correction.

This paper presents nanometer-scale production and metrology methods for elliptic-cylindrical x-ray mirrors with an unprecedentedly small tangential radius of curvature of 160 mm. Sub-millimeter-scale figure correction is conducted based on dynamic stencil deposition. The deposition flux through one or two shadow masks is examined by a comparison to a simple model. The masked deposition flux distribution is improved, leading to film thickness profiles that are 50 times sharper in terms of aspect ratio than those obtained using existing differential deposition approaches. Surface roughness deterioration is also effectively suppressed. A 2-mm-long 160-mm-radius mirror is produced with a width of 10 mm and measured using simple interferometry. The results are confirmed by conventional mirror metrology, contact profilometry, and x-ray ptychography. The x-ray focusing profile is diffraction-limited with a 142-nm focus size at a photon energy of 300 eV. The proposed methods have the potential to enhance the ultraprecise fabrication of highly curved mirrors, thus benefiting nanoscale photon-hungry x-ray techniques.

Management of nonviral mixed cryoglobulinemia vasculitis refractory to rituximab: Data from a European collaborative study and review of the literature.

BACKGROUND: Glucocorticoids (GCs) plus rituximab (RTX) represent the first-line treatment of nonviral mixed cryoglobulinemia vasculitis (CryoVas). However, data on therapeutic management and outcome of patients refractory to RTX are lacking. METHODS: We conducted a European collaborative retrospective multicenter study of patients with nonviral mixed CryoVas refractory to RTX and performed a literature review. RESULTS: Twenty-six original cases and 7 additional patients from the literature were included. All patients but one had type 2 cryoglobulinemia, and causes were autoimmune disease (51%), malignant hemopathy (12%) or essential CryoVas (42%). CryoVas was primary refractory to RTX in 42%, while 58% had an initial response to RTX before immune escape. After RTX failure, patients received a median of 1 (IQR, 1-3) line of treatment, representing 65 treatment periods during follow-up. Main treatments used were GCs in 92%, alkylating agents in 43%, RTX in combination with other treatments in 46%, and belimumab in 17%. Combination of anti-CD20 plus belimumab, alkylating agents alone and anti-CD20 plus alkylating agents provided the highest rates of clinical response in 100% 82% and 73%, respectively, but showed poor immunological response, in 50%, 30% and 38%, respectively. Rates of severe infection were 57%, 9% and 0% in patients receiving anti-CD20 plus belimumab, alkylating agents alone and anti-CD20 plus alkylating agents, respectively. CONCLUSION: In patients with nonviral mixed CryoVas refractory to RTX, anti-CD20 plus belimumab, and alkylating agents associated or not with anti-CD20, provide the highest rates of clinical response. However, anti-CD20 plus belimumab was frequently associated with severe infections.

Measurement techniques to improve the accuracy of x-ray mirror metrology using stitching Shack-Hartmann wavefront sensors.

We describe the development of specific measurement protocols to improve the accuracy of surface metrology of x-ray mirrors using a dedicated commercial instrument based on wavefront sensing techniques. This instrument, SHARPeR, uses measurements from a Shack-Hartmann wavefront sensor combined with a sub-aperture stitching method to provide two-dimensional maps of the surface slope errors and can measure curved mirrors above 1 m radii. In this paper, we describe the results of measurement methods developed on a SHARPeR system installed at the European Synchrotron (ESRF) to reduce the contribution of systematic errors to measurements of strongly curved spherical and aspherical x-ray mirrors with intrinsic slope errors of the order of 100-200 nrad rms. We demonstrate how this commercial integrated instrument can provide measurements of these mirrors with comparable accuracy to those measured with a long trace profiler.

Risk factors for symptomatic vascular events in giant cell arteritis: a study of 254 patients with large-vessel imaging at diagnosis.

AIMS: To identify factors associated with vascular events in patients with giant cell arteritis (GCA). METHODS: We performed a retrospective study of GCA patients diagnosed over a 20-year-period, who all underwent vascular imaging evaluation at diagnosis. Symptomatic vascular events were defined as the occurrence of any aortic event (aortic dissection or symptomatic aortic aneurysm), stroke, myocardial infarction, limb or mesenteric ischemia and de novo lower limbs arteritis stage 3 or 4. Patients with symptomatic vascular event (VE+) and without were compared, and risk factors were identified in a multivariable analysis. RESULTS: Thirty-nine (15.4%) of the 254 included patients experienced at least one symptomatic vascular event during follow-up, with a median time of 21.5 months. Arterial hypertension, diabetes, lower limbs arteritis or vascular complication at diagnosis were more frequent in VE+ patients (p < 0.05), as an abnormal computed tomography (CT)-scan at diagnosis (p = 0.04), aortitis (p = 0.01), particularly of the descending thoracic aorta (p = 0.03) and atheroma (p = 0.03). Deaths were more frequent in the VE+ group (37.1 versus 10.3%, p = 0.0003). In multivariable analysis, aortic surgery [hazard ratio (HR): 10.46 (1.41-77.80), p = 0.02], stroke [HR: 22.32 (3.69-135.05), p < 0.001], upper limb ischemia [HR: 20.27 (2.05-200.12), p = 0.01], lower limb ischemia [HR: 76.57 (2.89-2027.69), p = 0.009], aortic atheroma [HR: 3.06 (1.06-8.82), p = 0.04] and aortitis of the descending thoracic aorta on CT-scan at diagnosis [HR: 4.64 (1.56-13.75), p = 0.006] were independent predictive factors of a vascular event. CONCLUSION: In this study on GCA cases with large vessels imaging at diagnosis, aortic surgery, stroke, upper or lower limb ischemia, aortic atheroma and aortitis of the descending thoracic aorta on CT-scan, at GCA diagnosis, were independent predictive factors of a vascular event. PLAIN LANGUAGE SUMMARY: Risk factors for symptomatic vascular events in giant cell arteritisThis study was performed to identify the risk factors for developing symptomatic vascular event during giant cell arteritis (GCA) because these are poorly known.We performed a retrospective study of GCA patients diagnosed over a 20-year-period, who all underwent vascular imaging evaluation at diagnosis.Patients with symptomatic vascular event (VE+) and without (VE-) were compared, and risk factors were identified in a multivariable analysis.Thirty-nine patients experienced at least one symptomatic vascular event during follow-up, with a median time of 21.5 months.Arterial hypertension, diabetes, lower limbs arteritis or vascular complication at diagnosis were significantly more frequent in VE+ patients, as an abnormal CT-scan at diagnosis, aortitis, particularly of the descending thoracic aorta and atheroma. Deaths were more frequent in the VE+ group.Among 254 GCA patients, 39 experienced at least one vascular event during follow-up.Aortic surgery, stroke, upper and lower limb ischemia were vascular event risk factors.Aortic atheroma and descending thoracic aorta aortitis on CT-scan were vascular event risk factors.This study on GCA cases with large vessels imaging at diagnosis, showed that aortic surgery, stroke, upper or lower limb ischemia, aortic atheroma and aortitis of the descending thoracic aorta on CT-scan, at GCA diagnosis, were independent predictive factors of a vascular event.

Assessment of the efficacy and safety of tocilizumab in patients over 80 years old with giant cell arteritis.

OBJECTIVE: To assess the efficacy and tolerance of tocilizumab (TCZ) in giant cell arteritis (GCA) patients over 80. METHOD: GCA patients over 80 years old from the French Study Group for Large Vessel Vasculitis register who received TCZ were analyzed. RESULTS: Twenty-one GCA patients (median age 84 [81-90] years old, including nine over 85) received TCZ for the following nonexclusive reasons: glucocorticoid (GC)-sparing effect in 14, relapsing disease in 8, disease severity in 4, and/or failure of another immunosuppressant in 4. TCZ was introduced with GCs at diagnosis in 6 patients and at 8 [3-37] months after GC initiation in 15 others. After a median delay of 8 [2-21] months post-TCZ introduction, 14 (67%) patients were able to definitively stop GCs, including 6 who were GC-dependent before TCZ. At the last follow-up (median 20 [3-48] months), 11 (52%) patients had definitively stopped TCZ, and 2 additional patients had stopped but relapsed and resumed TCZ. Seven (33%) patients experienced 11 adverse events: hypercholesterolemia in 4 patients; infections, i.e., pyelonephritis, bronchitis, and fatal septic shock associated with mesenteric infarction following planned surgery (GCs were stopped for 1 year and TCZ infusions for 2 months), respectively, in 3 patients; moderate thrombocytopenia and moderate neutropenia in 2 patients; and a 5-fold increase in transaminase levels in another that improved after TCZ dose reduction. CONCLUSION: TCZ remains a valuable GC-sparing option in the oldest GCA patients with an interesting risk-benefit ratio. Mild-to-moderate adverse events were observed in one-third of patients.

Deleterious neurological impact of diagnostic delay in immune-mediated thrombotic thrombocytopenic purpura.

BACKGROUND: Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare life-threatening thrombotic microangiopathy requiring urgent therapeutic plasma exchange (TPE). However, the exact impact of a slight delay in TPE initiation on the subsequent patients' outcome is still controversial. AIM: We aimed to study the frequency, short-term neurological consequences, and determinants of diagnostic delay in iTTP. METHODS: We conducted a retrospective monocentric study including patients with a first acute episode of iTTP (2005-2020) classified into 2 groups: delayed (>24h from first hospital visit, group 1) and immediate diagnosis (≤24h, group 2). RESULTS: Among 42 evaluated patients, 38 were included. Eighteen cases (47%) had a delayed diagnosis (median: 5 days). The main misdiagnosis was immune thrombocytopenia (67%). The mortality rate was 5% (1 death in each group). Neurological events (stroke/TIA, seizure, altered mental status) occurred in 67% vs 30% patients in group 1 and 2, respectively (p = 0.04). Two patients in group 1 exhibited neurological sequelae. The hospital length of stay was longer in group 1 (p = 0.02). At the first hospital evaluation, potential alternative causes of thrombocytopenia were more prevalent in group 1 (33% vs 5%, p = 0.04). Anemia was less frequent in group 1 (67% vs 95%, p = 0.04). All patients had undetectable haptoglobin levels. By contrast, 26% of schistocytes counts were <1%, mostly in group 1 (62% vs 11%, p = 0.01). CONCLUSION: Diagnostic delay is highly prevalent in iTTP, with a significant impact on short-term neurological outcome. In patients with profound thrombocytopenia, the thorough search for signs of incipient organ dysfunction, systematic hemolysis workup, and proper interpretation of schistocytes count are the key elements of early diagnosis of TTP.

Large-vessel involvement is predictive of multiple relapses in giant cell arteritis.

BACKGROUND: Giant cell arteritis (GCA) is the most common systemic vasculitis. Relapses are frequent. The aim of this study was to identify relapse risk factors in patients with GCA with complete large-vessel imaging at diagnosis. METHODS: Patients with GCA followed in our institution between April 1998 and April 2018 were included retrospectively. We included only patients who had undergone large vascular imaging investigations at diagnosis by computed tomography (CT)-scan and/or positron emission tomography (PET)-scan and/or angio-magnetic resonance imaging (MRI). Clinical, biological, and radiological data were collected. Relapse was defined as the reappearance of GCA symptoms, with concomitant increase in inflammatory markers, requiring treatment adjustment. Relapsing patients (R) and non-relapsing patients (NR) were compared. Relapse and multiple relapses (>2) risk factors were identified in multivariable Cox analyses. RESULTS: This study included 254 patients (73.2% women), with a median age of 72 years at diagnosis and a median follow up of 32.5 months. At diagnosis, 160 patients (63%) had an inflammatory large-vessel involvement on imaging, 46.1% (117 patients) relapsed at least once, and 21.3% (54 patients) had multiple relapses. The median delay of first relapse after diagnosis was 9 months. The second relapse delay was 21.5 months. NR patients had more stroke at diagnosis than R (p = 0.03) and the brachiocephalic trunk was involved more frequently on CT-scan (p = 0.046), as carotids (p = 0.02) in R patients. Multivariate Cox model identified male gender [hazard ratio (HR): 0.51, confidence interval (CI) (0.27-0.96), p = 0.04] as a relapse protective factor, and peripheral musculoskeletal manifestations [HR: 1.74 (1.03-2.94), p = 0.004] as a relapse risk factor. Peripheral musculoskeletal manifestations [HR: 2.78 (1.23-6.28), p = 0.014], negative temporal artery biopsy [HR: 2.29 (1.18-4.45), p = 0.015], large-vessel involvement like upper limb ischemia [HR: 8.84 (2.48-31.56), p = 0.001] and inflammation of arm arteries on CT-scan [HR: 2.39 (1.02-5.58), p = 0.04] at diagnosis were risk factors of multiple relapses. CONCLUSION: Male gender was a protective factor for GCA relapse and peripheral musculoskeletal manifestations appeared as a relapsing risk factor. Moreover, this study identified a particular clinical phenotype of multi-relapsing patients with GCA, characterized by peripheral musculoskeletal manifestations, negative temporal artery biopsy, and large-vessel involvement with upper limb ischemia or inflammation of arm arteries. PLAIN LANGUAGE SUMMARY: At giant cell arteritis diagnosis, large-vessel inflammatory involvement is predictive of multiple relapses 46.1% of patients with GCA relapse, and 21.3% undergo multiple relapses;Male gender appears as a protective factor for relapsing in GCA;Peripheral musculoskeletal manifestations are a relapse and multiple relapses risk factor;A negative temporal artery biopsy is predictive of multiple relapses;Large-vessel involvement is predictive of multiple relapses.

Molecularly imprinted films and quaternary ammonium-functionalized microparticles working in tandem against pathogenic bacteria in wastewaters.

Despite major efforts to combat pollution, the presence of pathogenic bacteria is still detected in surface water, soil and even crops due to poor purification of domestic and industrial wastewaters. Therefore, we have designed molecularly imprinted polymer films and quaternary ammonium-functionalized- kaolin microparticles to target specifically Gram-negative bacteria (GNB) and Gram-positive bacteria (GPB) in wastewaters and ensure a higher purification rate by working in tandem. According to the bacteriological indicators, a reduction by 90 % was registered for GNB (total coliforms and Escherichia coli O157) and by 77 % for GPB (Clostridium perfringens) in wastewaters. The reduction rates were confirmed when using pathogen genetic markers to quantify particular types of GNB and GPB, like Salmonella typhimurium (reduction up to 100 %),Campylobacter jejuni (reduction up to 70 %), Enterococcus faecalis (reduction up to 81 %), Clostridium perfringens (reduction up to 97 %) and Shiga toxin-producing Escherichia coli (reduction up to 64 %). In order to understand the bactericidal activity of prepared films and microparticles, we have performed several key analyses such as Cryo-TEM, to highlight the auto-assembly mechanism of components during the films formation, and 29 Si/13 C CP/MAS NMR, to reveal the way quaternary ammonium groups are grafted on the surface of kaolin microparticles.

Composite Nanogels Based on Zeolite-Poly(ethylene glycol) Diacrylate for Controlled Drug Delivery.

This study presents the design of novel composites nanogels, based on poly(ethylene glycol) diacrylate and natural zeolite particles, that are able to act as materials with controlled drug delivery properties. Natural zeolite‒nanogels composite, with varying zeolite contents, were obtained by an inverse mini-emulsion technique and loaded with 5-fluorouracil, a widely used chemotherapeutic drug. Herein, the possibility of adjusting final properties by means of modifying the preparation conditions was investigated. The prepared composite nanogels are characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). In light of this tunable drug-loading capability, swelling behaviour, and cytotoxicity, these composite nanogels could be highly attractive as drug reservoirs.

Gamma heavy chain disease associated with large granular lymphocytic leukemia: A report of two cases and review of the literature.

OBJECTIVE AND IMPORTANCE: Gamma heavy chain diseases (γHCD) and large granular lymphocyte (LGL) leukemia are two rare lymphoproliferative diseases, respectively with B and T phenotype. Both γHCD and LGL leukemia share some similar clinical features, such as cytopenias, splenomegaly, and recurrent infections. Association of these two diseases is exceptional and suggest pathogenic link. We report two cases of γHCD associated with T-LGL leukemia. CLINICAL PRESENTATION: Patient 1 was a 70-year-old woman, with lymphoplasmacytic lymphoma, refractory to chlorambucil-rituximab treatment. She developed during the follow up a γHCD with T-LGL leukemia, unresponsive to melphalan, thalidomide, and steroids, requiring supportive care. Patient 2 was a 40-year-old man with chronic severe asymptomatic neutropenia, revealing both γHCD and T-LGL leukemia. He is still well without any treatment nor complications, with 7 years follow up. CONCLUSION: Several types of B lymphoproliferative disease are associated with LGL leukemia. Although exceptional, this association of two rare lymphoproliferative disorders, with a different phenotype, does not seem fortuitous.

Comparison of idiopathic (isolated) aortitis and giant cell arteritis-related aortitis. A French retrospective multicenter study of 117 patients.

OBJECTIVES: The aim of the study was to compare clinical/imaging findings and outcome in patients with idiopathic (isolated aortitis, IA) and with giant cell arteritis (GCA)-related aortitis. METHODS: Patients from 11 French internal medicine departments were retrospectively included. Aortitis was defined by aortic wall thickening >2mm and/or an aortic aneurysm on CT-scan, associated to inflammatory syndrome. Patients with GCA had at least 3 ACR criteria. Aortic events (aneurysm, dissection, aortic surgeries) were reported, and free of aortic events-survival were compared. RESULTS: Among 191 patients with non-infectious aortitis, 73 with GCA and 44 with IA were included. Patients with IA were younger (65 vs 70 years, p=0.003) and comprised more past/current smokers (43 vs 15%, p=0.0007). Aortic aneurisms were more frequent (38% vs 20%, p=0.03), and aortic wall thickening was more pronounced in IA. During follow-up (median=34 months), subsequent development of aortic aneurysm was significantly lower in GCA when compared to IA (p=0.009). GCA patients required significantly less aortic surgery during follow-up than IA patients (p=0.02). Mean age, sex ratio, inflammatory parameters, and free of aortic aneurism survival were equivalent in patients with IA ≥ 60 years when compared to patients with GCA-related aortitis. CONCLUSIONS: IA is more severe than aortitis related to GCA, with higher proportions of aortic aneurism at diagnosis and during follow-up. IA is a heterogeneous disease and its prognosis is worse in younger patients <60 years. Most patients with IA ≥ 60 years share many features with GCA-related aortitis.

Modeling the emergence of multi-protein dynamic structures by principles of self-organization through the use of 3DSpi, a multi-agent-based software.

BACKGROUND: There is an increasing need for computer-generated models that can be used for explaining the emergence and predicting the behavior of multi-protein dynamic structures in cells. Multi-agent systems (MAS) have been proposed as good candidates to achieve this goal. RESULTS: We have created 3DSpi, a multi-agent based software that we used to explore the generation of multi-protein dynamic structures. Being based on a very restricted set of parameters, it is perfectly suited for exploring the minimal set of rules needed to generate large multi-protein structures. It can therefore be used to test the hypothesis that such structures are formed and maintained by principles of self-organization. We observed that multi-protein structures emerge and that the system behavior is very robust, in terms of the number and size of the structures generated. Furthermore, the generated structures very closely mimic spatial organization of real life multi-protein structures. CONCLUSION: The behavior of 3DSpi confirms the considerable potential of MAS for modeling subcellular structures. It demonstrates that robust multi-protein structures can emerge using a restricted set of parameters and allows the exploration of the dynamics of such structures. A number of easy-to-implement modifications should make 3DSpi the virtual simulator of choice for scientists wishing to explore how topology interacts with time, to regulate the function of interacting proteins in living cells.

Supercoiled circular DNA and protein retention in non-equilibrium chromatography temperature and velocity dependence: testimony of a transition.

Non-equilibrium chromatography (NEC) is a chromatographic mode for the rapid separation of polymers. The retention behavior of various proteins (human, chicken, bovine serum albumin) and supercoiled circular double-stranded DNA (plasmids) was investigated using a phosphate buffer as a mobile phase at different velocities and column temperatures with a C1 column with very low-packing particle diameter as a stationary phase. It was shown that the two factors (temperature and velocity) constituted important parameters in the retention mechanism of plasmids and proteins in NEC. The protein was retained more than the plasmid. At all the temperatures (5, 10, 15, 20, 25 degrees C) the plasmid retention increased over the entire flow-rate range (0.02-1.8 ml/min). For the protein, the retention curve presented a decrease in the relative retention time until a critical value of the mobile phase flow-rate, followed by an increase. The transition between the two well known NEC methods, slalom chromatography and hydrodynamic chromatography was clearly visualized for proteins at the lowest temperature, but did not appear for plasmids due to their strong compact structure.