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Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care. Arthritis Care Res (Hoboken) 2023; 75:1553-1562. [PMID: 36775844 PMCID: PMC10500561 DOI: 10.1002/acr.25002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 07/14/2022] [Accepted: 08/16/2022] [Indexed: 11/10/2022]
Abstract
OBJECTIVE The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis. METHODS We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded. RESULTS We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers. CONCLUSION In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.
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Treatment escalation patterns to start biologics in refractory moderate juvenile dermatomyositis among members of the Childhood Arthritis and Rheumatology Research Alliance. Pediatr Rheumatol Online J 2023; 21:3. [PMID: 36609397 PMCID: PMC9825021 DOI: 10.1186/s12969-022-00785-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 12/26/2022] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Despite new and better treatments for juvenile dermatomyositis (JDM), not all patients with moderate severity disease respond adequately to first-line therapy. Those with refractory disease remain at higher risk for disease and glucocorticoid-related complications. Biologic disease-modifying antirheumatic drugs (DMARDs) have become part of the arsenal of treatments for JDM. However, prospective comparative studies of commonly used biologics are lacking. METHODS The Childhood Arthritis and Rheumatology Research Alliance (CARRA) JDM biologics workgroup met in 2019 and produced a survey assessing current treatment escalation practices for JDM, including preferences regarding use of biologic treatments. The cases and questions were developed using a consensus framework, requiring 80% agreement for consensus. The survey was completed online in 2020 by CARRA members interested in JDM. Survey results were analyzed among all respondents and according to years of experience. Chi-square or Fisher's exact test was used to compare the distribution of responses to each survey question. RESULTS One hundred twenty-one CARRA members responded to the survey (denominators vary for each question). Of the respondents, 88% were pediatric rheumatologists, 85% practiced in the United States, and 43% had over 10 years of experience. For a patient with moderately severe JDM refractory to methotrexate, glucocorticoids, and IVIG, approximately 80% of respondents indicated that they would initiate a biologic after failing 1-2 non-biologic DMARDs. Trials of methotrexate and mycophenolate were considered necessary by 96% and 60% of respondents, respectively, before initiating a biologic. By weighed average, rituximab was the preferred biologic over abatacept, tocilizumab, and infliximab. Over 50% of respondents would start a biologic by 4 months from diagnosis for patients with refractory moderately severe JDM. There were no notable differences in treatment practices between respondents by years of experience. CONCLUSION Most respondents favored starting a biologic earlier in disease course after trialing up to two conventional DMARDs, specifically including methotrexate. There was a clear preference for rituximab. However, there remains a dearth of prospective data comparing biologics in refractory JDM. These findings underscore the need for biologic consensus treatment plans (CTPs) for refractory JDM, which will ultimately facilitate comparative effectiveness studies and inform treatment practices.
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Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry. Pediatr Rheumatol Online J 2022; 20:107. [PMID: 36434731 PMCID: PMC9701017 DOI: 10.1186/s12969-022-00770-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 11/08/2022] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months. METHODS We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed. RESULTS We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05). CONCLUSION While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.
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Anti-Valosin-Containing Protein (VCP/p97) Autoantibodies in Inclusion Body Myositis and Other Inflammatory Myopathies. ACR Open Rheumatol 2022; 5:10-14. [PMID: 36373433 PMCID: PMC9837394 DOI: 10.1002/acr2.11510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 08/29/2022] [Accepted: 09/27/2022] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE The rationale for this study was based on reports that valosin-containing protein (VCP) mutations are found in hereditary inclusion body myositis (IBM) and VCP was detected in rimmed vacuoles of sporadic IBM (sIBM) muscle biopsies. Autoantibodies to VCP have not been reported in sIBM or other inflammatory myopathies (IIMs). The aim of this study was to determine the frequency and clinical significance of anti-VCP antibodies in sIBM and other IIMs. METHODS Sera were collected from 73 patients with sIBM and 383 comparators or controls, including patients with IIM (n = 69), those with juvenile dermatomyositis (JDM) (n = 67), those with juvenile idiopathic arthritis (JIA) (n = 47), those with primary biliary cholangitis (PBC) (n = 105), controls that were age matched to patients with sIBM (similarly aged controls [SACs]) (n = 63), and healthy controls (HCs) (n = 32). Immunoglobulin G antibodies to VCP were detected by addressable laser bead immunoassay using a full-length recombinant human protein. RESULTS Among patients with sIBM, 26.0% (19/73) were positive for anti-VCP. The frequency in disease controls was 15.0% (48/320). Among SACs, the frequency was 1.6% (1/63), and in HCs 0% (0/32). Frequencies were 17.5% (11/63) for IIM, 25.7% (27/105) for PBC, 3.0% (2/67) for JDM, and 17.0% (8/47) for JIA. The sensitivity, specificity, positive predictive value, and negative predictive value of anti-VCP for sIBM were 26.0%, 87.2%, 28.4%, and 85.9%, respectively. Of patients with sIBM, 15.1% (11/73) were positive for both anti-VCP and anti-cytosolic 5'-nucleotidase 1A (NT5c1A). Eleven percent of patients (8/73) were positive for anti-VCP, but negative for anti-NT5c1A. CONCLUSION Anti-VCP has low sensitivity and moderate specificity for sIBM but may help fill the seronegative gap in sIBM. Further studies are needed to determine whether anti-VCP is a biomarker for a clinical phenotype that may have clinical value.
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Dataset from a proteomics analysis of tumor antigens shared between an allogenic tumor cell lysate vaccine and pancreatic tumor tissue. Data Brief 2022; 44:108490. [PMID: 35959468 PMCID: PMC9357830 DOI: 10.1016/j.dib.2022.108490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 10/26/2022] Open
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Autologous dendritic cells pulsed with allogeneic tumour cell lysate induce tumour-reactive T-cell responses in patients with pancreatic cancer: A phase I study. Eur J Cancer 2022; 169:20-31. [PMID: 35490565 DOI: 10.1016/j.ejca.2022.03.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/09/2022] [Accepted: 03/16/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) is notorious for its poor prognosis even after curative resection. Responses to immunotherapy are rare and related to inadequate T-cell priming. We previously demonstrated the potency of allogeneic lysate-dendritic cell (DC) vaccination in a preclinical model. Here we translate this concept to patients. METHODS In this phase I study, patients with resected PDAC were included when they demonstrated no radiologic signs of recurrence after standard-of-care treatment. Allogeneic tumour lysate-loaded autologous monocyte-derived DCs were injected at weeks 0, 2, 4 and at months 3 and 6. Objectives are feasibility, safety and immunogenicity of allogeneic tumour-DCs. The presence of tumour antigens shared between the vaccine and patient tumours was investigated. Immunological analyses were performed on peripheral blood, skin and tumour. RESULTS Ten patients were included. DC production and administration were successful. All patients experienced a grade 1 injection-site and infusion-related reaction. Two patients experienced a grade 2 fever and 1 patient experienced a grade 3 dyspnoea. No vaccine-related serious adverse events were observed. Shared tumour antigens were found between the vaccine and patient tumours. All evaluated patients displayed a vaccine-induced response indicated by increased frequencies of Ki67+ and activated PD-1+ circulating T-cells. In addition, treatment-induced T-cell reactivity to autologous tumour of study patients was detected. Seven out of ten patients have not experienced disease recurrence or progression at a median follow-up of 25 months (15-32 months). CONCLUSION Allogeneic tumour lysate-DC treatment is feasible, safe and induces immune reactivity to PDAC expressed antigens.
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Gene Expression Profiles of Treatment Response and Non-Response in Children With Juvenile Dermatomyositis. ACR Open Rheumatol 2022; 4:671-681. [PMID: 35616642 PMCID: PMC9374052 DOI: 10.1002/acr2.11445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 01/26/2022] [Accepted: 02/01/2022] [Indexed: 12/26/2022] Open
Abstract
Objective The study objective was to identify differences in gene expression between treatment responders (TRs) and treatment non‐responders (TNRs) diagnosed with juvenile dermatomyositis (JDM). Methods Gene expression analyses were performed using whole blood messenger RNA sequencing in patients with JDM (n = 17) and healthy controls (HCs; n = 10). Four analyses were performed (A1‐4) comparing differential gene expression and pathways analysis exploiting the timing of sample acquisition and the treatments received to perform these comparative analyses. Analyses were done at diagnosis and follow‐up, which averaged 7 months later in the cohort. Results At diagnosis, the expression of 10 genes differed between TRs and TNRs. Hallmark and canonical pathway analysis revealed 11 and 60 pathways enriched in TRs and 3 and 21 pathways enriched in TNRs, respectively. Pathway enrichment at diagnosis in TRs was strongest in pathways involved in metabolism, complement activation, and cell signaling as mediated by IL‐8, p38/microtubule associated protein kinases (MAPK)/extracellular signal‐regulated kinases (ERK), Phosphatidylinositol 3 Kinase Gamma (PI3Kγ), and the B cell receptor. Follow‐up hallmark and canonical pathway analysis showed that 2 and 14 pathways were enriched in TRs, whereas 24 and 123 pathways were enriched in treatment TNRs, respectively. Prior treatment with glucocorticoids significantly altered expression of 13 genes in the analysis of subjects at diagnosis with JDM as compared with HCs. Conclusion Numerous genes and pathways differ between TRs and TNRs at diagnosis and follow‐up. Prior treatment with glucocorticoids prior to specimen acquisition had a small effect on the performed analyses.
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Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis. Pediatr Rheumatol Online J 2022; 20:18. [PMID: 35255941 PMCID: PMC8903717 DOI: 10.1186/s12969-022-00676-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/07/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry. METHODS In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months. RESULTS One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability. CONCLUSION High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.
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Pediatric GAD-65 Autoimmune Encephalitis: Assessing Clinical Characteristics and Response to Therapy With a Novel Assessment Scale. Pediatr Neurol 2022; 128:25-32. [PMID: 35032887 DOI: 10.1016/j.pediatrneurol.2021.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 12/11/2021] [Accepted: 12/18/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Glutamic acid decarboxylase (GAD) encephalitis is a neuroinflammatory disease characterized by a broad range of symptoms including cognitive deficits, behavioral changes, and seizures. Children with this disorder have heterogeneous presentations, and little is known about symptom progression over time and response to immunotherapy. METHODS This study reports 10 pediatric GAD encephalitis cases and symptoms found at presentation and follow-up. In addition, symptom severity was reported utilizing a novel scale evaluating functional outcomes across the domains affected by autoimmune encephalitis including cognition, language, seizures, psychiatric symptoms, sleep, and movement. Retrospective chart review was conducted for 10 patients aged <18 years, diagnosed with GAD encephalitis, and followed for one year or more. Chart review included clinical, imaging, and laboratory findings at time of diagnosis and at six- and 12-month follow-ups. RESULTS At presentation, cognitive deficits were found in all patients, seizures in six of 10, and language decline in seven of 10. Psychiatric symptoms were prominent for all but one patient with three of nine patients presenting with psychosis. Fatigue, sleep disruption, and movement disorders were less prominent symptoms, occurring in approximately half of the cohort. Cognition and fatigue improved significantly over time when compared with symptom severity, whereas seizures, psychiatric symptoms, and sleep did not. Language and sleep showed improvement only in early stages. Analysis of seizure frequency and type noted variability mirroring trends noted in adult studies of GAD encephalitis. CONCLUSIONS This study demonstrated the variability of symptom profiles of pediatric GAD encephalitis and benefits of symptom severity scales. Symptom profiles and progression vary in this population.
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Juvenile Dermatomyositis and Development of Malignancy: 2 Case Reports and a Literature Review. J Rheumatol 2020; 47:479. [PMID: 31941800 DOI: 10.3899/jrheum.190929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Mycophenolate mofetil in the treatment of pediatric autoimmune central nervous system disease. Dev Med Child Neurol 2019; 61:388. [PMID: 30474195 DOI: 10.1111/dmcn.14098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
PURPOSE OF REVIEW Autoimmune encephalitis (AE) is an increasingly recognized etiology for neuropsychiatric deficits that are highly responsive to immunotherapy. As a result, rheumatologists are often called upon to help with the diagnosis and treatment of these conditions. The purpose of this review is to provide an update on the pharmacologic treatment of AE. RECENT FINDINGS To date, there are no prospective randomized placebo-controlled trials to guide treatment recommendations for AE. First-line therapies include corticosteroids, intravenous immunoglobulin, and plasma exchange. Second-line therapies include rituximab and cyclophosphamide (CYC), as well as mycophenolate mofetil and azathioprine. For patients refractory to both first- and second-line therapy, there is emerging evidence for the interleukin-6 (IL-6) inhibitor tocilizumab, the proteasome inhibitor bortezomib, and low-dose IL-2. Early treatment initiation and treatment escalation in patients with refractory disease improve outcomes. Given the delayed time between dosing and treatment effects of second-line agents, continuing first-line treatment until the patients shows improvement is recommended. SUMMARY Although AE can present with dramatic, life-threatening neuropsychiatric deficits, the potential for recovery with prompt treatment is remarkable. First- and second-line therapies for AE lead to clinical improvement in the majority of patients, including full recoveries in many. Early treatment and escalation to second-line therapy in those with refractory disease improves patient outcomes. Novel treatments including IL-6 blockade and proteasome inhibitors have shown promising results in patients with refractory disease.
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A uniaxial stress capacitive dilatometer for high-resolution thermal expansion and magnetostriction under multiextreme conditions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:073903. [PMID: 27475567 DOI: 10.1063/1.4958957] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Thermal expansion and magnetostriction are directional dependent thermodynamic quantities. For the characterization of novel quantum phases of matter, it is required to study materials under multi-extreme conditions, in particular, down to very low temperatures, in very high magnetic fields or under high pressure. We developed a miniaturized capacitive dilatometer suitable for temperatures down to 20 mK and usage in high magnetic fields, which exerts a large spring force between 40 to 75 N on the sample. This corresponds to a uniaxial stress up to 3 kbar for a sample with cross section of (0.5 mm)(2). We describe design and performance test of the dilatometer which resolves length changes with high resolution of 0.02 Å at low temperatures. The miniaturized device can be utilized in any standard cryostat, including dilution refrigerators or the commercial physical property measurement system.
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Persistent Detwinning of Iron-Pnictide EuFe_{2}As_{2} Crystals by Small External Magnetic Fields. PHYSICAL REVIEW LETTERS 2014; 113:227001. [PMID: 25494081 DOI: 10.1103/physrevlett.113.227001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Indexed: 06/04/2023]
Abstract
Our comprehensive study on EuFe_{2}As_{2} reveals a dramatic reduction of magnetic detwinning fields compared to other AFe_{2}As_{2} (A=Ba, Sr, Ca) iron pnictides by indirect magnetoelastic coupling of the Eu^{2+} ions. We find that only ∼0.1 T are sufficient for persistent detwinning below the local Eu^{2+} ordering; above T_{Eu}=19 K, higher fields are necessary. Even after the field is switched off, a significant imbalance of twin domains remains constant up to the structural and electronic phase transition (190 K). This persistent detwinning provides the unique possibility to study the low temperature electronic in-plane anisotropy of iron pnictides without applying any symmetry-breaking external force.
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4kg solid replaces 80L liquid cleaner – innovative cleaner system for automated instrument reprocessing. BMC Proc 2011. [PMCID: PMC3239773 DOI: 10.1186/1753-6561-5-s6-p40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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5082 POSTER Identification of Protein Markers Predicting Chemotherapy Resistance in Breast Cancer. Eur J Cancer 2011. [DOI: 10.1016/s0959-8049(11)71524-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Symmetry-breaking lattice distortion in Sr₃Ru₂O₇. PHYSICAL REVIEW LETTERS 2011; 107:026404. [PMID: 21797628 DOI: 10.1103/physrevlett.107.026404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Indexed: 05/31/2023]
Abstract
The electronic nematic phase of Sr₃Ru₂O₇ is investigated by high-resolution in-plane thermal expansion measurements in magnetic fields close to 8 T applied at various angles Θ off the c axis. At Θ < 10° we observe a very small (10⁻⁷) lattice distortion which breaks the fourfold in-plane symmetry, resulting in nematic domains with interchanged a and b axis. At Θ ≳ 10° the domains are almost fully aligned and thermal expansion indicates an area-preserving lattice distortion of order 2 × 10⁻⁶ which is likely related to orbital ordering. Since the system is located in the immediate vicinity of a metamagnetic quantum critical end point, the results represent the first observation of a structural relaxation driven by quantum criticality.
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Abstract
BACKGROUND Peanuts and tree nuts are among the most common foods provoking severe allergic reactions including fatal anaphylaxis. However, little is known of the underlying genetic and immunological mechanisms involved. OBJECTIVE Based on findings in other allergic diseases, we have investigated whether specific human leucocyte antigens (HLA) are associated with nut allergy. METHOD Eighty-four patients presenting at the allergy clinic with symptoms of nut allergy were typed for the HLA Class I (HLA-A and B) and Class II (HLA-DRB1 and DQB1) loci by PCR using sequence-specific primers. Carriage frequencies were compared with 82 atopic non-nut-allergic subjects and 1798 random blood donors. RESULTS The frequency of HLA-B(*)07 (28.57%) and DRB1(*)11 (15.48%) was increased in the nut-allergic patients compared to the atopic controls (12.20% and 3.66%, respectively) but not when compared to the blood donors (28.86% and 10.12%). DRB1(*)13 and DQB1(*)06 were both increased in frequency in the nut allergy patients over both the atopic and blood donor controls. However, none of these increased frequencies were significant when corrected for the number of comparisons undertaken. CONCLUSION At HLA '2-digit resolution' and with undifferentiated patients with nut allergy, there are no major disturbances in the frequency of HLA-A, B, DRB1 or DQB1 types. However, the difference in frequency of HLA-DRB1(*)11 between the nut allergy patients and the atopic controls merits further investigation as this may represent an important phenotypic relationship.
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