Long Term Clinical Outcome and Quality of Life of Children, Adolescents and Young Adults Treated with Pencil Beam Scanning Proton Therapy for Rhabdomyosarcoma

PURPOSE/OBJECTIVE(S)

To assess the long-term clinical outcomes of children, adolescents and young adults (CAYAs) with rhabdomyosarcoma (RMS) treated with pencil beam scanning proton therapy (pbsPT).

MATERIALS/METHODS

One hundred twenty-one RMS (embryonal, n = 102; 84.3%) patients treated between January 2000 and December 2020 were included in this analysis. The median age was 4.7 years (range, 0.1-35.3). All patients received systemic chemotherapy according to prospective protocols. The median total dose delivered was 54 Gy (RBE) (range, 41.4-74.0).

RESULTS

After a median follow-up time of 85.5 month (range,3.4-240.0), we observed 23 local/regional and 12 distant failures. The estimated 5-year local control (LC) and overall survival (OS) was 81.5% and 80%, respectively. For the subgroups of parameningeal (PM), orbital, urogenital and H&N non-PM the 5-year LC was 74.7%, 92%, 100% and 66.7%. The corresponding figures for OS were 68.8%, 100%, 100%, and 66.7, respectively. The 5-year non-ocular Grade 3 toxicity free survival was 78.9%. At the start of pbsPT children and their caregivers reported QoL significantly worse than the norm group. QoL improved however over the follow up period to normal values in nearly all domains. Median of PEDQOL PROXY reported QoL in Normgroup (children: 4- 18 yrs) and RMS patients (n = 27-42 answers per domain): CONCLUSION: Excellent clinical outcome was observed for CAYAs with RMS treated with pbsPT. Two thirds of treatment failures were local. High-grade late non-ocular toxicity was manageable. QoL improved towards normal scores in nearly all domains after therapy.

Clinical features and genetic biomarkers associated with different phenotypes of systemic lupus erythematosus in Paraguayan patients

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by a heterogeneous clinical picture that makes the diagnosis and follow-up of these patients difficult. This study aimed to identify correlations between clinical, immunological, and genetic biomarkers and clinical manifestations in SLE. A retrospective study of data from medical records and immunological and genetic studies of SLE patients in Paraguay was carried out. A descriptive analysis was performed based on the type of variable. Human leukocyte antigen (HLA) allele frequencies (DPA1, DPB1, DQA1, DQB1, and DRB1) were calculated, and univariate logistic regression analyses were performed between each of the explanatory variables and the presence or absence of each phenotype. Odds ratios, 95% confidence intervals, and p values were recorded. Associations with p<0.05 were considered statistically significant. 104 SLE patients were included: 86% were female, with a mean age of 32.80±10.36 years. An association was identified between anti-double stranded DNA (anti-dsDNA) and the presence of the renal phenotype and between anti-dsDNA and the absence of the joint and hematological phenotypes. Immunoglobulin M isotype rheumatoid factor was associated with the absence of a renal phenotype. HLA-DQB1*02:02 and HLA-DRB1*07:01 were associated with the cutaneous phenotype. An association was identified between age at disease onset over 30 years and the presence of the joint phenotype. No other associations were identified. Potential clinical, immunological, and genetic biomarkers of phenotypes have been identified in SLE Paraguayan patients.

Domain wall propagation and pinning induced by current pulses in cylindrical modulated nanowires

The future developments in 3D magnetic nanotechnology require the control of domain wall dynamics by means of current pulses. While this has been extensively studied in 2D magnetic strips (planar nanowires), few reports on this exist in cylindrical geometry, where Bloch point domain walls are expected to have intriguing properties. Here, we report an investigation on cylindrical magnetic Ni nanowires with geometrical notches. An experimental work based on synchrotron X-ray magnetic circular dichroism (XMCD) combined with photoemission electron microscopy (PEEM) indicates that large current densities induce domain wall nucleation, while smaller currents move domain walls preferably antiparallel to the current direction. In the region where no pinning centers are present, we found a domain wall velocity of about 1 km s^-1. Thermal modelling indicates that large current densities temporarily raise the temperature in the nanowire above the Curie temperature, leading to nucleation of domain walls during the system cooling. Micromagnetic modelling with a spin-torque effect shows that for intermediate current densities, Bloch point domain walls with chirality parallel to the Oersted field propagate antiparallel to the current direction. In other cases, domain walls can be bounced from the notches and/or get pinned outside their positions. We thus found that current is not only responsible for domain wall propagation, but also is a source of pinning due to the Oersted field action.

Impact of endocrine disruptors from mother's diet on immuno-hormonal orchestration of brain development and introduction of the virtual human twin tool

Diet has long been known to modify physiology during development and adulthood. However, due to a growing number of manufactured contaminants and additives over the last few decades, diet has increasingly become a source of exposure to chemicals that has been associated with adverse health risks. Sources of food contaminants include the environment, crops treated with agrochemicals, inappropriate storage (e.g., mycotoxins) and migration of xenobiotics from food packaging and food production equipment. Hence, consumers are exposed to a mixture of xenobiotics, some of which are endocrine disruptors (EDs). The complex interactions between immune function and brain development and their orchestration by steroid hormones are insufficiently understood in human populations, and little is known about the impact on immune-brain interactions by transplacental fetal exposure to EDs via maternal diet. To help to identify the key data gaps, this paper aims to present (a) how transplacental EDs modify immune system and brain development, and (b) how these mechanisms may correlate with diseases such as autism and disturbances of lateral brain development. Attention is given to disturbances of the subplate, a transient structure of crucial significance in brain development. Additionally, we describe cutting edge approaches to investigate the developmental neurotoxicity of EDs, such as the application of artificial intelligence and comprehensive modelling. In the future, highly complex investigations will be performed using virtual brain models constructed using sophisticated multi-physics/multi-scale modelling strategies based on patient and synthetic data, which will enable a greater understanding of healthy or disturbed brain development.

[Nephrotic syndrome due to preeclampsia: Presentation, management and clinical evolution observed in 5 years experience]

INTRODUCTION

Nephrotic syndrome (NS) is rare during pregnancy. The main cause is severe pre-eclampsia (PR). Our aim was to describe the clinical presentation, analytical features, medical management, and progress of women with NS due to PE.

MATERIALS AND METHODS

A descriptive, retrospective study, conducted from 01/01/2017 to 01/01/2022 (5years). Women with a gestational age (GA) ≥20weeks were included in the study, hospitalised due to hypertensive disorders in pregnancy (HDP), with no evidence of kidney damage prior to gestation.

RESULTS

Of the 652 HDP, 452 PE and 21 NS were identified. Maternal age was 25±5.7 years, GA at diagnosis was 33.1±5.1 weeks. All the women had facial and peripheral oedema: 5 pleural effusion, 3 pericardial effusion, and 2 anasarca. Their p24 was 6.17±2.34grams (3.10-10.8), serum albumin 2.5±0.27g/dL (2.10-2.90), and serum cholesterol 281.4±21.7mg/dL (251-316). Thirteen developed maternal complications: acute kidney damage, pulmonary oedema, dilated cardiomyopathy, eclampsia, and HELLP syndrome. They all remained hypertensive postpartum, and required a combination of two to three antihypertensive drugs. They all received statins postpartum, and angiotensin converting enzyme (ACE) inhibitors to manage proteinuria. None developed hyperkalaemia or creatinine elevation. Hospital stay was 10.4±3.7days. All nephrotic range proteinuria parameters reversed prior to discharge. No deaths were recorded.

CONCLUSION

Presentation ranged from peripheral oedema to serous involvement. Severity of proteinuria varied. Use of ACE inhibitors did not precipitate hyperkalaemia or kidney failure. Maternal complications were frequent, but no deaths were recorded.

AB1436 INFECTIONS IN PATIENTS WITH RHEUMATIC DISEASES IN TREATMENT WITH BIOLOGIC THERAPY

Background

Patients with rheumatic diseases (RD) have a higher risk of developing infections due to disease and immunosupressor treatment factors1. Biologic disease -modifying antirheumatic drugs (bDMARD) have been associated with the development of opportunistic infections, nevertheless their impact on severe infections has not been consistent2.

Objectives

To describe the sociodemographic and clinical characteristics of patients with RD on bDMARD treatment with and without infections, using data from the Mexican Adverse Events Registry (BIOBADAMEX), as well as to identify factors associated with the presence of infections.

Methods

BIOBADAMEX is a Mexican ongoing cohort of patients using bDMARDs. In this analysis we included all patients registered in Biobadamex from 2016 to 2021. We compared sociodemographic, clinical and treatment characteristics between patients who developed infections with to those who did not. We used descriptive statistics, Chi square and Kruskal Wallis tests to analyze differences between the groups.

Results

A total of 780 patients registered in Biobadamex were included in this study, among them 42 (5%) patients presented infections and 738 (95%) did not. At baseline, patients had a median (IQR) age of 50 (40-58) years and median disease duration of 7 (3-15) years. The most common diagnosis was rheumatoid arthritis with 512 (66%) patients, followed by ankylosing spondylitis in 115 (15%), psoriatic arthritis in 44 (6%), systemic lupus erythematosus in 30 (4%) and idiopathic juvenile arthritis in 27 (3%) patients. Comorbidities were present in 351 (45%) of the patients. Conventional DMARD (cDMARD) were used by 626 (80%) patients, and 290 (37%) used steroids. The most frequently used bDMARDs were adalimumab in 166 (21%) patients, certolizumab in 129 (16%), tocilizumab in 103 (13%) and abatacept 94 (12%).

Table 1 shows baseline characteristics in the groups with and without infections. Patients with infections presented more severe adverse events 3 (7%) compared to those who did not 11 (2%), p=0.007, with a complete recovery without sequels. Most common infection site was skin (21%) followed by superior airways (12%). Most common infectious agents were gram negative bacteria. Only 2 patients presented bacteremia.

Table 1.

Patients baseline characteristics

Infectionn=42Without infectionn=738pFemale, n(%)33 (79)595 (80)0.74Age, median(IQR)50.9 (43-59)49.8 (40-58)0.58Disease duration (years), median (RIC)7.5 (2-16)7.0 (3-15)0.9Diagnostic, n(%): Rheumatoid arthritis25 (59)487 (66)0.42 Idiopathic Juvenile Arthritis0 (0)27 (4) Ankylosing Spondylitis6 (14)109 (15) Others11 (26)115 (15)Comorbidities, n(%):22 (52)329 (44.6)0.32Previous bDMARD, n(%):15 (36)271 (37)0.89Use of steroids, n(%):16 (38)274 (37)0.9cDMARD, n(%)33 (79)593 (80)0.77Severe Adverse Events, n(%)3 (7)11 (2)0.007  Outcome, n(%)Recovered without sequels3 (100)6 (55)p=0.34*Not recovered03 (27)Unknown02 (18)Infection site, n(%)Skin9 (21)Superior airways5 (12)Urinary tract4 (10)Agent, n(%)Gram- bacteria9 (21)Gram+ bacteria0 (0)Virus4 (14)

*Chi2

Conclusion

The frequency of infections in patients using bDMARD in Biobadamex is low compared to the frequency reported in similar studies in other countries3. The presence of infections was associated with more severe adverse events in general, which recovered completely without sequels.

References

[1]Wallis D. Curr Opin Rheumatol. 2014;26(4):404-9.

[2]Singh JA et al. Lancet. 2015;386(9990):258-65.

[3]Pérez-Sola MJ, et al. Med Clin (Barc). 2011;137(12):533-40.

Disclosure of Interests

VIJAYA RIVERA TERAN: None declared, David Vega-Morales: None declared, Sandra Sicsik: None declared, Fedra Irazoque-Palazuelos: None declared, Miguel A Saavedra: None declared, Julio Cesar Casasola: None declared, Sandra Carrilo: None declared, Angélica Peña: None declared, Angel Castillo Ortiz: None declared, Omar Eloy Muñoz-Monroy: None declared, Sergio Duran Barragan: None declared, Azucena Ramos: None declared, Luis Francisco Valdés Corona: None declared, Estefanía Torres Valdéz: None declared, Aleni Paz: None declared, ERICK ADRIAN ZAMORA-TEHOZOL: None declared, Alfonso Torres: None declared, Samara Mendieta: None declared, Daniel Xavier Xibille Friedmann: None declared, Francisco Guerrero: None declared, Natalia Santana: None declared, Miguel Vazquez: None declared, Claudia Zepeda: None declared, Melanea Rivera: None declared, Kitzia Alvarado: None declared, Deshire Alpizar-Rodriguez Consultant of: Scientific advisor for GSK, unrelated to this study., Employee of: Scientific advisor for GSK, unrelated to this study.

POS1447 SOCIODEMOGRAPHIC, CLINICAL AND TREATMENT DIFFERENCES OF RHEUMATIC DISEASES IN THREE MEXICAN REGIONS

Background

Rheumatic diseases prevalence and characteristics in Mexico may vary depending on the country´s region1. To acknowledge these differences is needed to develop focused strategies for early diagnosis and treatment2.

Objectives

Identify the sociodemographic, clinical and treatment characteristics of the rheumatic diseases in the different regions in Mexico using data from the Mexican Adverse Events Registry (BIOBADAMEX).

Methods

In this analysis we included all patients registered from 2016 to 2021. We described the prevalence in the northern region of Mexico (NR), central (CR) and southern region (SR). We compared sociodemographic, clinical and treatment characteristics between these three regions. We used descriptive statistics, Chi square and Kruskal Wallis tests to analyze differences between the groups.

Results

A total of 780 patients were included in this study, 248 patients (32%) were from the NR, 471 (60%) were from the CR and 61 (8%) from the SR. At baseline, patients had a median (IQR) age of 50 (40-58) years and median disease duration of 7 (3-15) years. NR patients had longer disease duration (9.7 years, p <0.001) and SR patients had higher BMI (29, p 0.001). Overall, 351 (45%) had comorbidities. In CR and SR more than the half of the patient had comorbidities, while in NR only 29% (p 0.001).

The most common diagnosis was rheumatoid arthritis with 512 (66%) patients, followed by ankylosing spondylitis in 115 (15%), psoriatic arthritis in 44 (6%), systemic lupus erythematosus in 30 (4%) and idiopathic juvenile arthritis in 27 (3%), this proportions were maintained when analyzed by regions. We found SR had higher DAS 28 and higher BASDAI (Table 1).

Table 1.

Baseline characteristics by region.

Northern regionn=248Central regionn=471Southern regionn=61pAge, median(IQR)49.7 (42-58)49.9 (38-58)51.6 (43-61)0.4Female, n(%)193 (78)383 (81)52 (85)0.33Body Mass Index, median (IQR)28 (25-32)26 (22-29)29 (26-32)0.001Disease duration (years), median (RIC)9.7 (5-16)5.9 (2-14)4.5 (1-10)0.001Diagnostic, n(%): Rheumatoid arthritis173 (70)300 (64)39 (64)0.001 Idiopathic Juvenile Arthritis3 (1)23 (5)1 (2) Ankylosing Spondylitis47 (19)59 (13)9 (15)Laboratory studies, n(%)Rheumatoid factor97 (39)274 (58)38 (62)0.001ACPA15 (6)68 (14)12 (19)0.001Disease activity scores, median (IQR) DAS284.8 (3-6)5.1 (4-6)5.2 (5-7)0.001 BASDAI2.8 (0-7)4.9 (2-7)8.0 (5-9)0.003Comorbidities, n(%)72 (29)247 (52)32 (52)0.001Previous bDMARD, n(%):136 (55)149 (32)1 (2)0.001Steroids, n(%):93 (38)155 (33)42 (69)0.001cDMARD, n(%)200 (81)373 (79)53 (87)0.4Cause of bDMARD discontinuation, n(%) aLack of efficacy85 (62)45 (33)2 (22)0.001Adverse Event4 (3)25 (18)3 (33)Pregnancy1 (1)3 (2)0(0)Loss of patient follow up10 (7)0 (0)2 (22)Remission23 (17)5 (4)0 (0)Others14 (10)59 (43)2(22)

a) 238 patients.

Glucocorticoids were used by 290 (37%) patients, SR had the highest use rate (69%, p <0.001) and 80% of the patients used conventional DMARDs (cDMARDs) with no differences between regions. Overall, the most used bDMARDs were adalimumab, certolizumab, tocilizumab and abatacept.

At the time of the analysis 238 (36%) had discontinued bDMARDs treatment, 132 (47%) due to lack of response, being this the most frequent cause reported overall, with the highest rate in NR (62%, p <0.001). All NR patients have social security compared to 83% in CR and 79% in SR.

Conclusion

There are regional differences between patients with rheumatic diseases registered in Biobadamex. It was remarkable that all patients form NR had social security, which may impact in the access to treatment. There were differences in the treatments between regions. The data from this analysis may be useful to policy makers, pharmaceutical companies and physicians. Differences in size samples between regions could have influenced in the results, further analyses will be performed in the future including more patients.

References

[1]Peláez-Ballestas I et al. J Rheumatol 2011;86;3-8.

[2]Chopra A et al. Best Pract Res Clin Rheumatol 2008;22:583-604.

Disclosure of Interests

VIJAYA RIVERA TERAN: None declared, David Vega-Morales: None declared, Sandra Sicsik: None declared, Fedra Irazoque-Palazuelos: None declared, Miguel A Saavedra: None declared, Julio Cesar Casasola: None declared, Sandra Carrilo: None declared, Angélica Peña: None declared, Angel Castillo Ortiz: None declared, Omar Eloy Muñoz-Monroy: None declared, Sergio Duran Barragan: None declared, Azucena Ramos: None declared, Luis Francisco Valdés Corona: None declared, Estefanía Torres Valdéz: None declared, Aleni Paz: None declared, ERICK ADRIAN ZAMORA-TEHOZOL: None declared, Alfonso Torres: None declared, Samara Mendieta: None declared, Daniel Xavier Xibille Friedmann: None declared, Francisco Guerrero: None declared, Natalia Santana: None declared, Miguel Vazquez: None declared, Claudia Zepeda: None declared, Melanea Rivera: None declared, Kitzia Alvarado: None declared, Deshire Alpizar-Rodriguez Consultant of: Scientific advisor for GSK, unrelated to this study., Employee of: Scientific advisor for GSK, unrelated to this study.

AB1461 IMPACT OF BASELINE DISEASE ACTIVITY ON DISCONTINUATION OF BIOLOGICAL DMARDS IN PATIENTS WITH RHEUMATOID ARTHRITIS: DATA FROM THE MEXICAN ADVERSE EVENTS REGISTRY (BIOBADAMEX)

Background

Decrease treatment persistence in rheumatoid arthritis (RA) patients has been associated with several factors, including number of previous biological DMARDs (bDMARDs), female gender and higher disease activity or lower function at baseline [1].

Objectives

Determine if drug discontinuation of bDMARDs differs by disease activity level at baseline in patients with RA in the Mexican Adverse Events Registry (BIOBADAMEX).

Methods

BIOBADAMEX is a Mexican ongoing cohort of patients using bDMARDs. In this analysis we included all patients with RA registered from 2016 to 2021 with at least two assessments. Survival on bDMARDs was estimated using Kaplan-Meier analysis. Predictors of discontinuation, including high disease activity defined as DAS28-ESR>5.1, were investigated by Cox regression analyses.

Results

Among 528 RA patients in the registry, 302 had at least two assessments. Of patients analyzed, 276 (91%) were women. At baseline, patients had a median (IQR) age of 52.7 (44-60) years old, median disease duration of 9.3 (4-16) months. A total of 142 (47%) had comorbidities, 34 (11%) had more than 2 morbidities. At baseline DAS28-ESR was 4.8 (4-6), 59 (20%) patients had low (DAS28-ESR<=3.2) and 130 (43%) had high disease activity. The most common bDMARDs received at baseline were abatacept 68 (23%), tocilizumab 59 (20%), adalimumab 50 (17%) and certolizumab 41 (14%). At the time of analysis, the median bDMARDs treatment duration was 17.2 (12-27) months. Overall, 130 (43%) patients had discontinued treatment, the most common causes of discontinuation were inefficacy in 64 patients, 15 for remission, 12 for adverse events and 26 for others. Figure 1 shows discontinuation rate curves in patients by disease activity. Cox proportional hazards demonstrated significant difference in bDMARD discontinuation between patients with baseline high disease activity (HR 1.3, 95% CI 1.1-1.7, p=0.03), but not differences were found regarding baseline age (HR 1.0, 95% CI 0.9-1.0, p=0.16), sex (HR 0.9, 95%CI 0.6-1.4), disease duration (HR 1.0, 95%CI 0.9-1.0, p=0.92), smoking (HR 1.2, 95% CI 0.7-2.1, p=0.44), number of comorbidities (HR 1.0, 95%CI 0.9-1.2, p=0.51) or other factors. The significant association of baseline high disease activity remained after adjusting by baseline age, sex, smoking, disease duration and number of comorbidities (HR 1.3, 95% CI 1.1-1.7, p=0.02).

Figure 1.

Discontinuation rate curves in RA patients with high disease activity (DAS28 >5.1) and DAS28<=5.1

Conclusion

In Mexican RA patients registered in BIOBADAMEX, we found that baseline high disease activity is associated with the discontinuation of bDMARDs. Further longitudinal analyses will be performed including more patients to assess retention rate of specific bDMARDs and identify predictive variables of discontinuation in Mexican population.

References

[1]Lauper K, Finckh A. Predictive factors of treatment persistence in rheumatoid arthritis. Joint Bone Spine. 2020 Dec;87(6):531-534.

Disclosure of Interests

VIJAYA RIVERA TERAN: None declared, David Vega-Morales: None declared, Sandra Sicsik: None declared, Fedra Irazoque-Palazuelos: None declared, Miguel A Saavedra: None declared, Julio Cesar Casasola: None declared, Sandra Carrilo: None declared, Angélica Peña: None declared, Angel Castillo Ortiz: None declared, Omar Eloy Muñoz-Monroy: None declared, Sergio Duran Barragan: None declared, Azucena Ramos: None declared, Luis Francisco Valdés Corona: None declared, Estefanía Torres Valdéz: None declared, Aleni Paz: None declared, ERICK ADRIAN ZAMORA-TEHOZOL: None declared, Daniel Xavier Xibille Friedmann: None declared, Francisco Guerrero: None declared, Natalia Santana: None declared, Miguel Vazquez: None declared, Claudia Zepeda: None declared, Melanea Rivera: None declared, Kitzia Alvarado: None declared, Deshire Alpizar-Rodriguez Consultant of: Scientific advisor for GSK, unrelated to this study., Employee of: Scientific advisor for GSK, unrelated to this study.

Evidence of Skyrmion-Tube Mediated Magnetization Reversal in Modulated Nanowires

Magnetic nanowires, conceived as individual building blocks for spintronic devices, constitute a well-suited model to design and study magnetization reversal processes, or to tackle fundamental questions, such as the presence of topologically protected magnetization textures under particular conditions. Recently, a skyrmion-tube mediated magnetization reversal process was theoretically reported in diameter modulated cylindrical nanowires. In these nanowires, a vortex nucleates at the end of the segments with larger diameter and propagates, resulting in a first switching of the nanowire core magnetization at small fields. In this work, we show experimental evidence of the so-called Bloch skyrmion-tubes, using advanced Magnetic Force Microscopy modes to image the magnetization reversal process of FeCoCu diameter modulated nanowires. By monitoring the magnetic state of the nanowire during applied field sweeping, a detected drop of magnetic signal at a given critical field unveils the presence of a skyrmion-tube, due to mutually compensating stray field components. That evidences the presence of a skyrmion-tube as an intermediate stage during the magnetization reversal, whose presence is related to the geometrical dimensions of the cylindrical segments.

AB0193 PRESENCE OF SUBLINICAL SYNOVITIS IN A ESTABLISHED RHEUMATOID ARTHRITIS COHORT

Background:

Some studies prove that a significant percentage of patients with rheumatoid arthritis (RA) in sustained clinical remission has radiological progression or joint damage, and the presence of residual activity objectified by imaging studies such as ultrasonography could be related to a relapse or flare of RA.(1,2)

Objectives:

To determine the presence of subclinical synovitis measured by ultrasonography in patients with RA on sustained clinical remission from the Rheumatology service at Hospital de Clínicas, San Lorenzo, Paraguay.

Materials and Methods:

Prospective, cross sectional, descriptive study, in RA patients meeting ACR/EULAR 2010 criteria, older than 18 years, on sustained clinical remission (≥6 months), measured by ESR-DAS28 (<2,6), doing follow-ups on our service. A healthy control group was included. All groups signed informed consent. Synovial hypertrophy (SH) and intraarticular vascularization grades on Power Doppler (PD) mode were determined according to EULAR recommendations and OMERACT 7 group definitions. Clinical data were obtained from the service’s registries.

SPSS 23rd version was used for data analysis. Quantitative variables were presented as means and qualitative as frequencies. Chi square test was performed for comparisons between dichotomous variables and t Student for continuous. For comparisons between variables the Spearman’s rank correlation coefficient was performed, and p≤0.05 for statistical significance. Factors predicting subclinical synovitis were analyzed with Odds Ratio (OR) CI 95%.

Results:

From 147 patients, 31 (21%) met remission criteria; 87.1% women, mean age 51.9±14.8 years. Mean disease duration was 9,06±10,81 years. 64,5% were RF and ACPA positive and 25,9% had erosions.

Ultrasonograms were made in 20 joints of both hands: radiocarpals (RC), metacarpophalangeals (MCP) and proximal interphalangeals (PIP). 12 patients (38.7%) presented subclinical synovitis (SH≥2+PD), more frequently on RC (29% right, 22.6% left), and MCP (9.7% on 2RMCP, 9.7% 4LMCP). These patients had greater CDAI (3.9±1.37 vs 2.89±1.15, p=0.03), HAQ (0.14±0.29 vs 0.00±0.00, p=0.04), CRP (9.90±7.46 vs 4.74±2.30, p=0.00) RF levels (502.67±275.66 vs 200.92±158.43, p=0,00), greater prednisone (16.5% vs 3.2%, p=0.04), and methotrexate use (20.16±5.54 vs 17.50±3.98, p=0.01). None of the healthy controls presented subclinical synovitis.

In binary logistic regression CRP levels, RF titers and methotrexate doses were associated to subclinical synovitis. This association is not found in multivariate logistic regression. Negative association was found between subclinical synovitis and two csDMARDs use.

Conclusion:

This is the first study of its type in Paraguayan patients, which clearly evidenced that an important part of RA patients in clinical remission still presented subclinical synovitis (HS≥2 + PD). It was associated with CRP, RF and methotrexate dose.

References:

[1]Płaza M, Nowakowska-Płaza A, Pracoń G, Sudoł-Szopińska I. Role of ultrasonography in the diagnosis of rheumatic diseases in light of ACR/EULAR guidelines. J Ultrason. marzo de 2016;16(64):55-64.

[2]Foltz V, Gandjbakhch F, Etchepare F, Rosenberg C, Tanguy ML, Rozenberg S, et al. Power Doppler ultrasound, but not low-field magnetic resonance imaging, predicts relapse and radiographic disease progression in rheumatoid arthritis patients with low levels of disease activity. Arthritis & Rheumatism. 2012;64(1):67-76.

Disclosure of Interests:

None declared

AB0015 STUDY OF VDR AND VDBP GENES AS CANDIDATE SUSCEPTIBILITY GENES FOR THE DEVELOPMENT OF IMMUNE-MEDIATED DISEASES IN THE PARAGUAYAN POPULATION

Background:

Immune Mediated Inflammatory Diseases (IMIDs) are complex diseases that are believed to have a strong interaction between the genome and the environment as part of their aetiology. In studies using the candidate gene strategy, genetic variation in a gene where functionality has been associated with the pathophysiology of the disease under study is being analyzed. In the last decade, polymorphisms of the vitamin D receptor (VDR) and VDBP genes have been more emphatically studied in IMIDs in different populations, but the results reported have not yet been conclusive.

Objectives:

To identify an association between vitamin D receptor (VDR) and vitamin D-binding protein (VDBP) gene polymorphisms, and IMIDs in Paraguayan patients.

Methods:

Association study of VDR (SNPs rs731236, rs7975232, rs2228570) and VDBP (rs4588) gene polymorphisms with susceptibility to IMIDs in Paraguayan population. A total of 399 patients with IMIDs (i.e. Systemic Lupus Erythematosus (SLE), Scleroderma (ES), Rheumatoid Arthritis (RA), and Cutaneous Psoriasis (CPS) and 100 hypernormal controls (HC) from the same population were included in this study. Genotyping was performed using Taqman real-time PCR-based technology (Life Technologies, USA). Statistical analysis was performed using Rv3.0.1 statistical language software (www.R-project.org). A p value ≤ 0.05 was used for statistical significance.

Results:

A total of 399 individuals, 100 controls and 299 patients (99 RA, 100 SLE, 50 ES, and 50 PSO) were included. Seventy-six percent were female and 24% were male. The mean age was 43.7±14 years. Four SNPs were genotyped: rs731236, rs7975232, rs2228570, rs4588. The HWE test was not statistically significant for any of the 4 SNPs considered (P>0.05), confirming the quality of genotyping and the absence of technical bias. (Table 1).

Table 1.

Genotyping of SNPs of the VDR and VDBP gene in Paraguayan population with IMIDs.

SNPIMIDMinor AlleleMajor AlleleMAFControlMAFCaseORIC.LIC.Hp allelicP.Geneticrs731236SLEGA0.50.40.640.420.970.0350.08rs731236RAGA0.50.410.690.461.050.0710.12rs731236SSGA0.50.420.710.421.180.180.37rs731236CPSGA0.50.380.60.361.010.0490.042rs2228570SLEAG0.360.381.140.741.740.60.45rs2228570RAAG0.360.310.830.531.280.40.56rs2228570SSAG0.360.361.020.61.7310.057rs2228570CPSAG0.360.391.160.681.960.610.83rs7975232SLECA0.360.320.820.531.260.40.072rs7975232RACA0.360.290.720.461.120.140.064rs7975232SSCA0.360.220.490.270.880.0120.0064rs7975232CPSCA0.360.411.210.722.030.450.016rs4588SLETG0.230.271.240.7720.420.48rs4588RATG0.230.220.930.561.530.810.84rs4588SSTG0.230.210.890.471.650.770.76rs4588CPSTG0.230.291.370.762.430.260.53

Conclusion:

There is evidence of nominal association between VDR SNPs: rs731236 (in SLE and CPS), and rs7975232 (in SS and CPS) and the presence of IMIDs disease in Paraguayan patients.

Disclosure of Interests:

None declared

POS0642 THE IMPACT OF AGE ON DISCONTINUATION OF BIOLOGIC DMARDs IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:

Rheumatoid arthritis (RA) is the most common autoimmune disease. Older patients treated with biologic DMARDs (bDMARDs) are at a significantly greater risk of adverse effects (AEs) [1]. However, the rate of drug discontinuation because of adverse effects caused by bDMARDs has not differed in elderly compared to younger patients in different registries.

Objectives:

Determine if drug discontinuation of bDMARDs differs by age in patients with rheumatoid arthritis in the Mexican Adverse Events Registry (BIOBADAMEX).

Methods:

BIOBADAMEX is a Mexican ongoing cohort of patients using bDMARDs since 2016. In this analysis we included all patients with diagnosis of RA with at least two assessments. Survival on bDMARDs was estimated using Kaplan-Meier analysis. Predictors of discontinuation, including age older than median age in the sample were investigated by Cox regression analyses.

Results:

Among 743 patients in the registry, 497 had RA diagnosis, from which, 214 had at least two assessments. At baseline, patients had a median (IQR) age of 53.4 (45-61) years old, median disease duration of 10.7 (6-17) months and median DAS28 of 4.7 (3-6). Conventional DMARDS were used by 185 (87%) patients and 94 (44%) patients used corticosteroids. Comorbidities were present in 194 (91%). The most common bDMARDs received at baseline were abatacept 59 (27%), tocilizumab 45(21%), adalimumab 31 (15%) and certolizumab 30 (14%). At the time of analysis, the median bDMARDs treatment duration was 21.0(13-34) months, 128 (59%) had discontinued treatment, 66 for inefficacy, 32 for adverse events and 30 for others. Fig 1 shows discontinuation rate curves in patients younger and older than median age. Cox proportional-hazards demonstrated no significant differences regarding age older than median age (HR 1.1, 95% CI 0.8-1.4, p=0.7), female sex (HR 1.2, 95% CI 0.7-1.9, p=0.44), use of corticosteroids (HR 1.2, 95% CI 0.9-1.6, p=0.20), comorbidities (HR 0.9, 95% 0.6-1.5, p=0.78), DAS28 (HR 0.9, 95% 0.9-1.1, p=0.93) or other factors.

Figure 1.

Discontinuation rate curves in patients younger and older than median age (< 53.4 and >=53.4 years old)

Conclusion:

This analysis did not show a role of age on discontinuation of bDMARDs in Mexican RA patients. Further longitudinal analyses will be performed including more patients to assess retention rate of bDMARDs and identify predictive variables of discontinuation in Mexican population.

References:

[1]Akter R, et al. Can Geriatr J. 2020 May 1;23(2):184-189.

[2]Ikari Y, et al. Medicine (Baltimore). 2020 Dec 24;99(52):e23861.

Disclosure of Interests:

None declared

Distribution of Burkholderia cepacia complex species isolated from industrial processes and contaminated products in Argentina

Burkholderia cepacia complex (Bcc) members have clinical relevance as opportunistic pathogens in patients with cystic fibrosis and are responsible of numerous nosocomial infections. These closely related bacteria are also reported as frequent contaminants of industrial products. In this retrospective study, we use PCR and recA gene sequence analysis to identify at species level Bcc isolates recovered from massive consumption products and industrial processes in Argentina during the last 25 years. The sequences obtained were also compared with recA sequences from clinical Bcc isolates deposited in GenBank database. We detected Bcc in purified water and preserved products from pharmaceutics, cosmetics, household cleaning articles, and beverages industries. B. contaminans (which is prevalent among people with cystic fibrosis in Argentina) was the most frequent Bcc species identified (42% of the Bcc isolates studied). B. cepacia (10%), B. cenocepacia (5%), B. vietnamiensis (16%), B. arboris (3%), and the recently defined B. aenigmatica (24%) were also detected. Rec A sequences from all B. cepacia and most B. contaminans industrial isolates obtained in this study displayed 100% identity with recA sequences from isolates infecting Argentinean patients. This information brings evidence for considering industrial massive consumption products as a potential source of Bcc infections. In addition, identification at species level in industrial microbiological laboratories is necessary for a better epidemiological surveillance. Particularly in Argentina, more studies are required in order to reveal the role of these products in the acquisition of B. contaminans infections.

Neoantigen prediction and computational perspectives towards clinical benefit: recommendations from the ESMO Precision Medicine Working Group

BACKGROUND

The use of next-generation sequencing technologies has enabled the rapid identification of non-synonymous somatic mutations in cancer cells. Neoantigens are mutated peptides derived from somatic mutations not present in normal tissues that may result in the presentation of tumour-specific peptides capable of eliciting antitumour T-cell responses. Personalised neoantigen-based cancer vaccines and adoptive T-cell therapies have been shown to prime host immunity against tumour cells and are under clinical trial development. However, the optimisation and standardisation of neoantigen identification, as well as its delivery as immunotherapy are needed to increase tumour-specific T-cell responses and, thus, the clinical efficacy of current cancer immunotherapies.

METHODS

In this recommendation article, launched by the European Society for Medical Oncology (ESMO), we outline and discuss the available framework for neoantigen prediction and present a systematic review of the current scientific evidence.

RESULTS

A number of computational pipelines for neoantigen prediction are available. Most of them provide peptide major histocompatibility complex (MHC) binding affinity predictions, but more recent approaches incorporate additional features like variant allele fraction, gene expression, and clonality of mutations. Neoantigens can be predicted in all cancer types with high and low tumour mutation burden, in part by exploiting tumour-specific aberrations derived from mutational frameshifts, splice variants, gene fusions, endogenous retroelements and other tumour-specific processes that could yield more potently immunogenic tumour neoantigens. Ongoing clinical trials will highlight those cancer types and combinations of immune therapies that would derive the most benefit from neoantigen-based immunotherapies.

CONCLUSIONS

Improved identification, selection and prioritisation of tumour-specific neoantigens are needed to increase the scope of benefit from cancer vaccines and adoptive T-cell therapies. Novel pipelines are being developed to resolve the challenges posed by high-throughput sequencing and to predict immunogenic neoantigens.

FRI0546 GENDER DIFFERENCES OF RHEUMATIC DISEASES IN MEXICAN POPULATION: DATA FROM THE MEXICAN BIOLOGICS REGISTRY

Background:

Most autoimmune diseases are more prevalent in women. Symptom severity, disease progression, response to therapy and overall survival differ between males and females with rheumatic diseases.

Objectives:

To identify the characteristics of autoimmune diseases presentation and treatment between male and female population using information from the Mexican Adverse Events Registry (BIOBADAMEX).

Methods:

BIOBADAMEX is a Mexican ongoing cohort that collects the information of patients using biologic and biosimilar drugs since 2016. For this study we included all patients enrolled in the registry and compared baseline clinical and disease characteristics, treatment and presence of adverse events between genders. We used logistic regression to analyze univariable associations.

Results:

A total of 655 participants were analysed, of which 82% were female (Table 1). We found women were older with a median of 53 years compared to 46 years in men (OR 1.02, CI 1.0-1.1). Smoking was higher in men (16%) compared to women (5%), (OR 0.3, CI 0.2-0.6). Women had longer disease duration, 9 years compared to 7 years in men (OR 1, CI 1.0-1.1). Rheumatoid arthritis (RA) was more prevalent in women (OR 2.7, CI 1-6.9), while ankylosing spondylitis (AS) and psoriatic arthritis (PsA) were more prevalent in men (OR 0.2, CI 0.1-0.4, and OR 0.3, CI 0.1-0.9 respectively). Women had more comorbidities than men (OR 1.8, CI 1.1-2.8) and used steroids more frequently (OR 1.7, CI 1.1-2.7). Differences in disease activity were not found, however we noticed high activity scores among participants.

Table 1.

Baseline characteristics in the cohort by sex

Womenn=532 (82%)Menn=123 (18%)UnivariableaOR(95%CI)Age, median (IQR)53 (44-60)47 (34-55)1.02 (1.0-1.1)*Body Mass Index, median (IQR)27 (23-31)26 (23-30)1.0 (0.9-1.1)Smoking, n(%)28 (5)18 (16)0.3 (0.2- 0.6)*Disease duration, median (IQR)9 (4-16)7 (2-13)1.0 (1.0-1.1)*Diagnosis, n(%): RA414 (78)37 (30)2.4 (1.0-5.7)* AIJ12 (2)5 (4)0.5 (0.1-1.9) AS37 (7)56 (46)0.1 (0.1-0.4)* PsA19 (4)15 (12)0.3 (0.1-0.8)* SLE17 (3)3 (2)1.2 (0.3-5.2) Others33 (6)7 (6)1Disease Activity indexes, median (IQR) DAS28a4.9 (3.6-5.9)4.9 (3.0-5.9)1.1 (0.9-1.3) BASDAIb4.8 (2.9-8)5.3 (2.8-7.5)0.9 (0.8- 1.1) ASDASc3.2 (1.9-4.5)3.9 (2.5-4.7)0.8 (0.6-1.2) SLEDAId14.5 (5.0-19.5)25 (25.0-31.0)0.6 (0.4-1.1)High blood pressure, n(%)77 (15)14 (12)1.3 (0.7-2.4)Diabetes mellitus, n(%)46 (9)7 (6)1.5 (0.7-3.5)High cholesterol, n(%)41 (8)8 (7)1.2 (0.4-2.6)Other comorbidities, n(%):173 (33)26 (21)1.8 (1.1 -2.8)*Use of previous biologic, n(%):216 (40)44 (36)1.2 (0.8- 1.8)Use of steroids, n(%):215 (42)34 (29)1.7 (1.1 -2.7)*Use of DMARD, n(%):418 (79)89 (72)1.4 (0.9-2.2)Adverse eventsb, n(%):69 (13)14 (11)1.2 (0.7-2.1) Severeb, n(%):12 (17)3 (21)0.8 (0.2-3.1)

Univariable logistic regression analysis. *p<0.05.an=469,bn=99,cn=71,dn=19,

Table 1.

Analysis of association between change (Δ) in FMD and relevant parameters by univariate and multivariate linear regression analysis.

UnivariateRho (p)MultivariateBeta (p)Δ FMD (%)(r2=0.30)ChangeADMA (µmol/l)-0.63 (<0.001)-0.25 (0.01)MDA (nmol/ml)-0.58 (<0.001)-0.18 (0.02)SOD (U/ml)0.48 (<0.001)NSGSH (U/ml)0.02 (0.75)NSHOMA-0.21 (0.001)NSeGFR (ml/min/ 1.73 m2)-0.03 (0.62)NShsCRP (mg/l)-0.45 (<0.001)NSPTX3 (ng/ml)-0.49 (<0.001)-0.21 (0.01)SBP (mmHg)-0.26 (<0.001)NSDBP (mmHg)-0.11 (0.12)NSHemoglobin (g/dl)0.07 (0.32)NSTotal Cholesterol (mg/dl)-0.05 (0.49)NSTriglyceride (mg/dl)-0.11 (0.12)NSLDL (mg/dl)-0.12 (0.07)NSHDL (mg/dl)0.02 (0.82)NSHbA1c (%)-0.26 (<0.001)NSFigure 1.

Scatter-plot graphs between FMD and ADMA, MDA, CuZn-SOD, PTX-3.

Conclusion:

In our study we found sex differences regarding age and disease duration, being higher in women. As expected, the prevalence of RA was higher in women and AS and PsA in men. Overall, women used more steroids than men. An interesting finding was that patients had high disease activity. Future longitudinal analyses will allow us to analyse sex differences in disease progression and treatment response.

References:

[1] Ortona E et al. Ann Ist Super Sanita 2016;52(2):205-12

[2] Ngo ST et al. Front Neuroendocrinol 2014;3(3):347-69

Disclosure of Interests:

Vijaya Rivera Teran: None declared, Deshire Alpizar-Rodriguez: None declared, Sandra Sicsik: None declared, Fedra Irazoque-Palazuelos Consultant of: Bristol-Myers Squibb, Janssen, Pfizer Inc, Roche and UCB, Dafhne Miranda: None declared, David Vega-Morales: None declared, Julio Cesar Casasola: None declared, Sandra Carrilo: None declared, angel castillo: None declared, Sergio Duran Barragan: None declared, Omar Muñoz: None declared, Aleni Paz: None declared, Angélica Peña: None declared, Alfonso Torres: None declared, Daniel Xavier Xibille Friedmann Consultant of: Lilly, Abbvie, Speakers bureau: Lilly, Abbvie, Azucena Ramos: None declared, José Francisco Moctezuma: None declared, Francisco Aceves: None declared, Estefania Torres: None declared, Natalia Santana: None declared, Miguel Vazquez: None declared, Erick Zamora: None declared, Francisco Guerrero: None declared, Claudia Zepeda: None declared, Melanea Rivera: None declared, Kitzia Alvarado: None declared, Cesar Francisco Pacheco Tena: None declared

LRP1-Mediated AggLDL Endocytosis Promotes Cholesteryl Ester Accumulation and Impairs Insulin Response in HL-1 Cells

The cardiovascular disease (CVD) frequently developed during metabolic syndrome and type-2 diabetes mellitus is associated with increased levels of aggregation-prone small LDL particles. Aggregated LDL (aggLDL) internalization is mediated by low-density lipoprotein receptor-related protein-1 (LRP1) promoting intracellular cholesteryl ester (CE) accumulation. Additionally, LRP1 plays a key function in the regulation of insulin receptor (IR) and glucose transporter type 4 (GLUT4) activities. Nevertheless, the link between LRP1, CE accumulation, and insulin response has not been previously studied in cardiomyocytes. We aimed to identify mechanisms through which aggLDL, by its interaction with LRP1, produce CE accumulation and affects the insulin-induced intracellular signaling and GLUT4 trafficking in HL-1 cells. We demonstrated that LRP1 mediates the endocytosis of aggLDL and promotes CE accumulation in these cells. Moreover, aggLDL reduced the molecular association between IR and LRP1 and impaired insulin-induced intracellular signaling activation. Finally, aggLDL affected GLUT4 translocation to the plasma membrane and the 2-NBDG uptake in insulin-stimulated cells. We conclude that LRP1 is a key regulator of the insulin response, which can be altered by CE accumulation through LRP1-mediated aggLDL endocytosis.

Isolation of five Enterobacteriaceae species harbouring blaNDM-1 and mcr-1 plasmids from a single paediatric patient

In Argentina, NDM metallo-β-lactamase was first reported in 2013. By now, it has disseminated throughout the country in diverse Gram negative bacteria. Here, we report the case of a paediatric patient that underwent a 1-year hospitalisation due to erythrodermic psoriasis in 2014 and received multiple antimicrobial treatments. During his stay, five isolates were obtained from rectal swabs (rs) or blood culture (bc) suspicious of carbapenemase production: a K. quasipneumoniae subsp. quasipneumoniae (rs), Citrobacter freundii (rs), Escherichia coli (bc), Enterobacter cloacae (rs), and a Serratia marcescens (bc). The isolates were studied with broth microdilution, biparental conjugation and plasmid and whole genome sequencing (Illumina). All isolates harboured an 138,998-bp type 1 IncC plasmid that carried bla_NDM-1, ble_MBL, bla_CMY-6, rmtC, aac(6’)-Ib, and sul1 resistance genes. Additionally, the bla_NDM-plasmids contained ISKpn8 an insertion sequence previously described as associated only to bla_KPC. One isolate, a colistin-resistant E. coli, also carried a mcr-1-containing an IncI2 plasmid, which did not harbour additional resistance. The whole genome of K. quasipneumoniae subsp. quasipneumoniae isolate was fully sequenced. This isolate harboured, additionally to bla_NDM, three plasmid-mediated quinolone resistance genes: qnrB4, qnrB52 and aac(6’)-Ib-cr1. The E. cloacae isolate also harboured qnrA1. These findings alert to the underestimated horizontal dissemination of multidrug-resistant plasmids limiting treatment options with last resort antimicrobials.

Modeling magnetic-field-induced domain wall propagation in modulated-diameter cylindrical nanowires

Domain wall propagation in modulated-diameter cylindrical nanowires is a key phenomenon to be studied with a view to designing three-dimensional magnetic memory devices. This paper presents a theoretical study of transverse domain wall behavior under the influence of a magnetic field within a cylindrical nanowire with diameter modulations. In particular, domain wall pinning close to the diameter modulation was quantified, both numerically, using finite element micromagnetic simulations, and analytically. Qualitative analytical model for gently sloping modulations resulted in a simple scaling law which may be useful to guide nanowire design when analyzing experiments. It shows that the domain wall depinning field value is proportional to the modulation slope.

Duplex Ultrasound Evaluation for Dialysis access Selection and Maintenance: A Practical Guide

Detailed case directed history and examination is the mainstay of dialysis access modality selection, ie site and type of access, as well as for maintenance of dialysis access for longevity. As a logical step following history and physical examination, duplex ultrasound evaluation (DUE) is the most cost effective and non-invasive screening tool for evaluation for access placement and for assessment of an established access. Pre-operative vascular mapping allows selection of the optimal dialysis access modality and site. In established accesses, duplex ultrasound testing will diagnose the majority of vascular access complications and direct proper surgical or interventional radiology management. This review outlines a practical decision-making algorithm using DUE for choosing and managing the dialysis access.

Doubling of the magnetic energy product in ferromagnetic nanowires at ambient temperature by capping their tips with an antiferromagnet

We present an approach to prepare free-standing tips of micrometer-long nanowires electrodeposited in anodic aluminum oxide nanopores. Such open tips can be further processed, e.g. for vertical interconnects of functional layers or for tailoring the magnetization reversal of ferromagnetic nanowires. The magnetic switching of nanowires is usually initiated by vortex or domain formation at the nanowire tips. We show that coating the tips of Fe₃₀Co₇₀ nanowires (diameter 40 nm, length 16 μm) with thin antiferromagnetic Fe₅₀Mn₅₀ capping layers (thickness ≈10 nm) leads to magnetic hardening with a more than doubled energy product at ambient temperature.

Co/Au multisegmented nanowires: a 3D array of magnetostatically coupled nanopillars

Arrays of multisegmented Co/Au nanowires with designed segment lengths and diameters have been prepared by electrodeposition into aluminum oxide templates. The high quality of the Co/Au interface and the crystallographic structure of Co segments have determined by high-resolution transmission electron microscopy. Magnetic hysteresis loop measurements show larger coercivity and squareness of multisegmented nanowires as compared to single segment Co nanowires. The complementary micromagnetic simulations are in good agreement with the experimental results, confirming that the magnetic behavior is defined mainly by magnetostatic coupling between different segments. The proposed structure constitutes an innovative route towards a 3D array of synchronized magnetic nano-oscillators with large potential in nanoelectronics.

Leptin resistance elicits depressive-like behaviors in rats

There is a growing appreciation that the complications of obesity extend to the central nervous system (CNS) and include increased risk for development of neuropsychiatric co-morbidities such as depressive illness. The neurological consequences of obesity may develop as a continuum and involve a progression of pathological features which is initiated by leptin resistance. Leptin resistance is a hallmark feature of obesity, but it is unknown whether leptin resistance or blockage of leptin action is casually linked to the neurological changes which underlie depressive-like phenotypes. Accordingly, the aim of the current study was to examine whether chronic administration of a pegylated leptin receptor antagonist (Peg-LRA) elicits depressive-like behaviors in adult male rats. Peg-LRA administration resulted in endocrine and metabolic features that are characteristic of an obesity phenotype. Peg-LRA rats also exhibited increased immobility in the forced swim test, depressive-like behaviors that were accompanied by indices of peripheral inflammation. These results demonstrate that leptin resistance elicits an obesity phenotype that is characterized by peripheral immune changes and depressive-like behaviors in rats, supporting the concept that co-morbid obesity and depressive illness develop as a continuum resulting from changes in the peripheral endocrine and metabolic milieu.

Acute administration of reboxetine reduces alcohol self-administration but, after a subchronic treatment with this drug, alcohol self-administration is enhanced

Introduction

Comorbidity between alcoholism and depression has long been acknowledged, and the possibility that similar brain mechanisms, involving both serotonergic (5-HT) and noradrenergic systems (NE), underlie both pathologies has been suggested. Thus, inhibitors of NE and 5HT uptake have been proposed for the treatment of alcoholism, as they have shown to reduce alcohol intake in various animal models. However, most of the studies mentioned were carried out acutely and there is a lack of knowledge of the possible long-term effects. Clinical studies report an overall low efficacy of antidepressant treatment on alcohol consumption, or even a worsened prognosis. In addition, several cases of alcohol dependence following antidepressant treatment have been reported in the literature.

Objectives

We aimed at comparing the acute and chronic effects of the treatment with the antidepressant drug reboxetine on alcohol consumption.

Methods

We used a rat model of alcohol self-administration, and two different schedules of reboxetine administration (acute and chronic).

Results

Our results confirm the acute suppressant effects of reboxetine on alcohol consumption but indicate that, when this drug is administered chronically in a period of abstinence from alcohol, it can significantly increase the rate of alcohol self-administration.

Conclusions

These results are important for the understanding of the clinical reports describing cases of increased alcohol consumption after antidepressant treatment, and suggest that much more research is needed to fully understand the long term effects of antidepressants, which remain the most widely prescribed class of drugs.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Reversible morphological changes of assembled supramolecular amphiphiles triggered by pH-modulated host–guest interactions

Acid–base modulated host–guest binding at the micellar–water interface triggers reversible oblate ellipsoid-to-lamellar morphological transitions revealing the relationship between and morphology.

Angular first-order reversal curves: an advanced method to extract magnetization reversal mechanisms and quantify magnetostatic interactions

The magnetic properties of ordered hexagonal arrays of Co nanowires (NWs) and nanotubes (NTs) with diameters of 50 nm and interwire/tube distances of 105 nm were studied using first-order reversal curves (FORCs). We report an advanced analysis of angle dependent first-order reversal curves (AFORCs), measured by changing the angle of the applied magnetic field from θ = 0° (parallel to the wire/tube axis) to 90° (perpendicular). This method allowed us to determine the magnetization reversal mode and to retrieve quantitative information on the magnetostatic interactions between NWs and between NTs. In particular, we found a sharp increase in the coercivity distribution of the NT arrays for θ > 70°, which is attributed to a transition between vortex and transverse reversal modes. Local magnetic interactions are found to prevail in the Co NT arrays, steadily increasing from θ = 0° to 90°. However, in the Co NW arrays the mean magnetic interactions decrease as θ increases, going from ones similar to local interactions to ones smaller than them.

Integrated interdisciplinary training in the radiological sciences

The radiation sciences are increasingly interdisciplinary, both from the research and the clinical perspectives. Beyond clinical and research issues, there are very real issues of communication between scientists from different disciplines. It follows that there is an increasing need for interdisciplinary training courses in the radiological sciences. Training courses are common in biomedical academic and clinical environments, but are typically targeted to scientists in specific technical fields. In the era of multidisciplinary biomedical science, there is a need for highly integrated multidisciplinary training courses that are designed for, and are useful to, scientists who are from a mix of very different academic fields and backgrounds. We briefly describe our experiences running such an integrated training course for researchers in the field of biomedical radiation microbeams, and draw some conclusions about how such interdisciplinary training courses can best function. These conclusions should be applicable to many other areas of the radiological sciences. In summary, we found that it is highly beneficial to keep the scientists from the different disciplines together. In practice, this means not segregating the training course into sections specifically for biologists and sections specifically for physicists and engineers, but rather keeping the students together to attend the same lectures and hands-on studies throughout the course. This structure added value to the learning experience not only in terms of the cross fertilization of information and ideas between scientists from the different disciplines, but also in terms of reinforcing some basic concepts for scientists in their own discipline.

Co nanostructures in ordered templates: comparative FORC analysis

A comparative study on the structural and magnetic properties of highly ordered hexagonal arrays of Co nanoholes, nanowires, nanopillars and nanotubes, with tuned pore/wire/tube diameters, is here presented. The magnetic interactions and their dependence on the geometric features of the arrays were studied using first-order reversal curves (FORCs). For all nanostructures we observe an increase of the magnetostatic interactions with the templates' pore diameter, with the higher (smaller) values found for the nanowire (nanohole) arrays. For the smallest diameters studied (35 nm), all types of arrays could be considered as almost isolated nanostructures, where local interactions prevail. In particular, both nanotube and nanohole arrays exhibit considerable local magnetostatic interactions coming from the stray fields within each void or empty core. On the other hand, the coercivity is found to decrease with diameter for the elongated nanostructures, while it increases with the pore diameter for the nanohole arrays. This behavior is associated with the magnetization reversal mechanisms present in each array. This work highlights a versatile route to tailor the size, geometrical arrangement and magnetostatic interactions of ordered arrays and demonstrates their importance for the tuning of the magnetic behavior of nanometric devices.

Correlations among magnetic, electrical and magneto-transport properties of NiFe nanohole arrays

In this work, we use anodic aluminum oxide (AAO) templates to build NiFe magnetic nanohole arrays. We perform a thorough study of their magnetic, electrical and magneto-transport properties (including the resistance R(T), and magnetoresistance MR(T)), enabling us to infer the nanohole film morphology, and the evolution from granular to continuous film with increasing thickness. In fact, different physical behaviors were observed to occur in the thickness range of the study (2 nm < t < 100 nm). For t < 10 nm, an insulator-to-metallic crossover was visible in R(T), pointing to a granular film morphology, and thus being consistent with the presence of electron tunneling mechanisms in the magnetoresistance. Then, for 10 nm < t < 50 nm a metallic R(T) allied with a larger anisotropic magnetoresistance suggests the onset of morphological percolation of the granular film. Finally, for t > 50 nm, a metallic R(T) and only anisotropic magnetoresistance behavior were obtained, characteristic of a continuous thin film. Therefore, by combining simple low-cost bottom-up (templates) and top-down (sputtering deposition) techniques, we are able to obtain customized magnetic nanostructures with well-controlled physical properties, showing nanohole diameters smaller than 35 nm.

Tailoring the physical properties of thin nanohole arrays grown on flat anodic aluminum oxide templates

The introduction of voids in a magnetic thin-film alters the stray field distribution and enables the tailoring of the corresponding physical properties. Here we present a detailed study on thin magnetic nanohole arrays (NhAs) grown on top of hexagonally-ordered anodic aluminum oxide (AAO) substrates. We address the effect of AAO topography on the corresponding electrical and magneto-transport properties. Optimization of the AAO topography led to NhAs with improved resistance and magnetoresistance responses, while retaining their most important feature of enhanced coercivity. This opens new pathways for the growth of more complex structures on AAO substrates, a crucial aspect for their technological viability.

Domain wall dynamics in amorphous and nanocrystalline FeCoMoB microwires

We have studied the domain wall dynamics in amorphous and nanocrystalline FeCoMoB microwires. The domain wall propagation velocity has been found very fast (up to 5000 m/s) for the as-cast sample. Annealing at 575 K/1 h leads to the stress relief and sample homogenization and the domain wall velocity even increases to 5300 m/s. However, the domain wall dynamics is highly sensible to the temperature of a measurement. Annealing at 775 K/1 h leads to the appearance of the nanocrystalline structure with much higher temperature stability. The maximum domain wall velocity decreases (2800 m/s), however the domain wall dynamics is much stable with the temperature.

Analysis of the PKR-eIF2alpha phosphorylation homology domain (PePHD) of hepatitis C virus genotype 1 in HIV-coinfected patients by ultra-deep pyrosequencing and its relationship to responses to pegylated interferon-ribavirin treatment

Chronic coinfection with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) is among the greatest challenges facing public health worldwide. In this population, the response to hepatitis C therapy by treatment with pegylated interferon plus ribavirin (PEG-IFN+RBV) is lower than in HCV-monoinfected patients, particularly in those infected by HCV genotype 1. A PKR/eIF-2α phosphorylation homology domain (PePHD) within the E2 protein has been found to interact with PKR and inhibit PKR in vitro, suggesting a possible mechanism for HCV to evade the antiviral effects of IFN. The aim of this work was to analyze the amino acid conservation in the HCV-E2-PePHD and quasispecies diversity among HCV-HIV-coinfected patients exhibiting sustained virological response, non-response, or partial response with viral relapse to PEG-IFN+RBV by ultra-deep pyrosequencing. For this purpose, HCV-E2-PePHD PCR products were generated and sequenced directly for four patients with a sustained response, seven patients with no virological response, and four patients with viral relapse before and after treatment with PEG-IFN+RBV. HCV-E2-PePHD amino acid sequences were obtained for isolates from serum collected before and during treatment (24 h, 4 weeks, and 12 weeks). Quasispecies analysis of the HCV-E2-PePHD and flanking genomic regions was performed using 454/Roche pyrosequencing, analyzing 39,364 sequence reads in total. The HCV-E2-PePHD sequence at the amino acid and nucleotide level was highly conserved among HCV genotype 1 strains, irrespective of the PEG-IFN+RBV response. This high degree of amino acid conservation and sporadic mutations in the HCV-E2-PePHD domain do not appear to be associated with treatment outcome. The HCV-E2-PePHD sequence before or during treatment cannot be used to predict reliably the outcome of treatment in patients coinfected with HCV genotype 1 and HIV.