Influence of BDNF Val66Met genetic polymorphism in Major Depressive Disorder and Body Mass Index: Evidence from a meta-analysis of 6481 individuals

BACKGROUND

Major depressive disorder (MDD) and obesity are global health problems that frequently co-occur. Among shared etiological factors, genetic variation at the brain-derived neurotrophic factor (BDNF) gene is interesting since its implication in energy balance regulation, food intake and synaptic function. Thus, the aim of this study was to investigate the influence of the BDNF Val66Met polymorphism in relation to MDD and body mass index (BMI) in two large independent cohorts.

METHODS

The sample consisted of 2646 individuals with MDD and 3835 controls from the PISMA-ep and Radiant studies. Linear regressions were performed to test the association between the polymorphism and BMI and the interaction between the polymorphism and MDD on BMI. A meta-analysis across cohorts was conducted.

RESULTS

No association was found between the polymorphism and BMI. However, we found an association with MDD, showing these individuals higher BMI than controls in both cohorts. No differences were found in BMI depending on Val66Met genotype and no interaction between this polymorphism and MDD in relation to BMI was found. Although a tendency towards an interaction was found in the Radiant sample, the results of the meta-analysis did not support this finding.

LIMITATIONS

The use of self-reported height and weight measures to calculate BMI values.

CONCLUSIONS

We provide evidence for an association between BMI and MDD confirming previous results. Our meta-analysis including two large cohorts showed no interaction between BDNF, BMI and MDD. Future studies will be needed to confirm the role of this polymorphism in the relationship between BMI and MDD.

Quenching of oscillations via attenuated coupling for dissimilar electrochemical systems

The coupled dynamics of two similar and disparate electrochemical cells oscillators are analyzed. For the similar case, the cells are intentionally operated at different system parameters such that they exhibit distinct oscillatory dynamics ranging from periodic to chaotic. It is observed that when such systems are subjected to an attenuated coupling, implemented bidirectionally, they undergo a mutual quenching of oscillations. The same holds true for the configuration wherein two entirely different electrochemical cells are coupled via bidirectional attenuated coupling. Therefore, the attenuated coupling protocol seems to be universally efficient in achieving oscillation suppression in coupled oscillators (similar or heterogeneous oscillators). The experimental observations were verified by numerical simulations using appropriate electrodissolution model systems. Our results indicate that quenching of oscillations via attenuated coupling is robust and therefore could be ubiquitous in coupled systems with a large spatial separation prone to transmission losses.

Independent-noise provoked spiking, synchronized via coupling

We report experimental and numerical evidence of synchronized spiking phenomena provoked by the interaction of two bidirectionally coupled electrochemical systems subjected to independent stochastic input signals. To this end, the anodic potentials of two such systems were diffusively coupled. The corresponding anodic currents of these systems exhibited excitable fixed point behavior in the vicinity of a homoclinic bifurcation. Following this, the anodic potentials were perturbed by independent noise signals. The invoked oscillatory dynamics are analyzed using normalized variance and cross-correlation coefficient. By systematically varying the coupling strength between the systems and the level of external noise, regions exhibiting synchronized spiking behavior were identified.

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.

An alternate approach to simulate the dynamics of perturbed liquid drops

Liquid drops when subjected to external periodic perturbations can execute polygonal oscillations. In this work, a simple model is presented that demonstrates these oscillations and their characteristic properties. The model consists of a spring-mass network such that masses are analogous to liquid molecules and the springs correspond to intermolecular links. Neo-Hookean springs are considered to represent these intermolecular links. The restoring force of a neo-Hookean spring depends nonlinearly on its length such that the force of a compressed spring is much higher than the force of the spring elongated by the same amount. This is analogous to the incompressibility of liquids, making these springs suitable to simulate the polygonal oscillations. It is shown that this spring-mass network can imitate most of the characteristic features of experimentally reported polygonal oscillations. Additionally, it is shown that the network can execute certain dynamics, which so far have not been observed in a perturbed liquid drop. The characteristics of dynamics that are observed in the perturbed network are polygonal oscillations, rotation of network, numerical relations (rational and irrational) between the frequencies of polygonal oscillations and the forcing signal, and that the shape of the polygons depends on the parameters of perturbation.

Aperiodic bursting dynamics of active rotors

We report experiments on an active camphor rotor. A camphor rotor is prepared by infusing camphor on a regular rectangular paper strip. It performs self-propelled motion at the air-water interface due to Marangoni driven forces. After some transient (periodic) dynamics, the rotor enters into the aperiodic bursting regime, which is characterized as an irregularly repeated rest (halt) and run (motion) of the rotor. Subsequently, this aperiodic (irregular) rotor is entrained to a periodic (regular) regime with the help of a suitable external periodic forcing. Furthermore, we conducted experiments on two such coupled aperiodic camphor rotors. In this set of experiments, synchronized bursting was observed. During this bursting motion, one rotor follows the movement of the other rotor. A numerical point particle model, incorporating excitable underlying equations, successfully replicated experimentally observed aperiodic bursting.

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

Early acoustic experience alters genome-wide methylation in the auditory forebrain of songbird embryos

Early exposure to salient cues can critically shape the development of social behaviors. For example, both oscine birds and humans can hear and learn to recognize familiar sounds in ovo and in utero and recognize them following hatching and birth, respectively. Here we demonstrate that different chronic acoustic playbacks alter genome-wide methylation of the auditory forebrain in late-stage zebra finch (Taeniopygia guttata) embryos. Within the same subjects, immediate early gene activation in response to acute con- or heterospecific song exposure is negatively correlated with methylation extent in response to repeated daily prior exposure to the same type of stimuli. Specifically, we report less relative global methylation following playbacks of conspecific songs and more methylation following playbacks of distantly-related heterospecific songs. These findings offer a neuroepigenomic mechanism for the ontogenetic impacts of early acoustic experiences in songbirds.

Systematic review and meta-analysis of placebo-controlled invasive interventions for the management of chronic stable angina

Background

The benefits of invasive therapies for chronic stable angina are in large part supported by open label studies comparing invasive procedures to medical therapy alone. Placebo effects are frequently unaccounted for as control arms rarely receive placebo (sham) interventions.

This review pools studies comparing invasive therapies for chronic stable angina to placebo interventions and aims to measure the true effects of different invasive interventions.

Methods

We performed a systematic review and meta-analysis of double blinded randomized placebo-controlled trials of invasive therapies for the management of chronic stable angina. The outcomes of interest were change in exercise tolerance time, change in Canadian cardiovascular society angina grade and rate of post-procedural complications including myocardial infarction and all-cause mortality.

Results

Six randomized placebo-controlled trials were included, with a total of 742 participants. Median follow-up ranged from 6 weeks to 16 months. Contrary to data reported in individual studies, pooled analysis favored invasive therapies over placebo procedures: exercise tolerance time was higher (standard mean difference (SMD) 35.2 seconds [4.4- 66.0]), angina scores were more likely to improve by ≥1 class (Odds Ratio (OR) 2.16 [1.05- 4.46]) and by ≥2 classes (OR 1.76 [1.13- 2.74]). There was no difference in post-procedural myocardial infarction (incidence rate ratio (IRR) 2.91 [0.61–13.93]) and all-cause mortality (IRR 0.39 [0.35–4.27]).

Conclusions

This meta-analysis of placebo-controlled trials for chronic stable angina found a beneficial effect from invasive therapies. This favorable effect has not been seen in individual studies. Our findings suggest that sample sizes should be adjusted upwards in placebo-controlled studies to detect true treatment effects independent of the placebo effect.

Funding Acknowledgement

Type of funding source: None

Explosive synchronization in temporal networks: A comparative study

We present a comparative study on Explosive Synchronization (ES) in temporal networks consisting of phase oscillators. The temporal nature of the networks is modeled with two configurations: (1) oscillators are allowed to move in a closed two-dimensional box such that they couple with their neighbors and (2) oscillators are static and they randomly switch their coupling partners. Configuration (1) is further studied under two possible scenarios: in the first case, oscillators couple to fixed numbers of neighbors, while, in the other case, they couple to all oscillators lying in their circle of vision. Under these circumstances, we monitor the degrees of temporal networks, velocities, and radius of circle of vision of the oscillators and the probability of forming connections in order to study and compare the critical values of the coupling required to induce ES in the population of phase oscillators.

Thiol/disulfide exchange occurs in rotavirus structural proteins during contact with intestinal villus cell surface

Protein disulfide isomerase (PDI) is an enzyme that catalyzes disulfide bond reduction or formation and rearrangements of disulfide bridges, and also functions as a chaperone. During entry of some of the viruses PDI participates in thiol-disulfide exchange. Previous reports show that rotavirus entry is interfered by impermeant thiol/disulfide exchange inhibitors and antibodies against PDI. Our objective was to assess the interaction between PDI and triple-layered particles (TLPs) from rotavirus strains ECwt and RRV and from a human rotavirus isolate (HI) during the early steps of virus entry in a system of isolated small intestinal villi. Purified soluble PDI was incubated with either isolated intestinal villi or cell membrane-enriched fractions in the presence or absence of thiol/disulfide inhibitors such as bacitracin, DTNB or N- ethylmaleimide followed by the assessment of the PDI interactions with TLPs and rotavirus structural proteins in terms of their redox state changes. Soluble and membrane-bound PDI was found to interact with TLPs from all the rotaviruses assayed and also with the isolated structural proteins represented by the recombinant rVP5* (a tryptic cleavage product of VP4), rVP6 and the native VP7. PDI interaction with TLPs and rotavirus structural proteins was decreased by the presence of thiol/disulfide exchange inhibitors. Interactions of cell membrane-enriched fractions with TLPs produced rearrangements in the disulfide bridges of rotavirus structural proteins. We conclude that PDI interacts with rotavirus virions through redox reactions that could facilitate the rotavirus entry into the host cell. Keywords: cell surface PDI; thiol-disulfide exchange; rotavirus TLPs; virus entry; bacitracin; DTNB.

Estimated direct costs of non-small-cell lung cancer by stage and care phase: a whole disease model

Background

Non-small-cell lung cancer (NSCLC) is the first cause of cancer-related death among men and the second among women worldwide. It also poses an economic threat to the sustainability of healthcare services. This study estimates the direct costs of care for patients with NSCLC by stage at diagnosis and management phase of pathway recommended in local and international guidelines.

Methods

Based on the most up-to-date guidelines we developed a detailed “whole-disease” model that lists the probabilities of all potentially necessary diagnostic and therapeutic actions involved in the management of each stage of NSCLC. Then we assigned the cost sustained by the public authorities to each procedure, obtaining an estimate of the total and average per-patient costs of each stage of the disease and management phase in Veneto Region, Italy.

Results

The mean expected cost of a patient with NSCLC is 22,968 € in the first year: 20,222 € in stage I, 23,935 € in stage II, 23,027 € in stage III, 22,915 € in stage IV and 31,749 € for Pancoast's tumors. In the second year the mean per patient-costs patient ranged from 2,722 €, for a patient with stage I disease, to 13,396 € for a patient with stage IV, with an overall average cost of 8,307 €. In the early stages, the main cost was due to surgery, whereas in the more advanced stages radiotherapy, medical therapy, treatment for progressions and supportive care become variously more important.

Conclusions

Our study enabled a prediction of the direct costs and outcomes for patients diagnosed with NSCLC on a two-year timeline after the diagnosis. An estimation of the direct costs of NSCLC, and in general for cancer, appears fundamental to predict the burden of new oncological therapies and treatments on healthcare services, and, in our opinion, our model could represent a useful tool for policy-makers in the optimization of resources allocation.

Key messages

Whole disease model allows an economic evaluation of a clinical pathway. The model is able to estimate direct costs of NSCLC by disease stage and management phase within a time horizon of two years. High cost-surgery makes the early stages no less expensive than advanced stages during the first year. In the second year, an advanced stage case costs almost five times more than an early stage case.

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

Online Clinic, a New Method of Delivering Psychotherapy

Introduction

Psychotherapy is one of the most widely investigated and practiced forms of treatment used in the treatment of different mental health problems. However, there are some barriers in delivering this treatment, including long waiting lists, therapist shortage and lack of access to therapists in remote areas. Therefore, using alternative methods to overcome these barriers seems necessary.

Method

The division of psychiatry at Queen's university provides different psychotherapy groups for individuals suffering from different kinds of mental health problem. We gave the participants the opportunity to choose online psychotherapy through an online clinic or the live group sessions. All the patients were assessed by different questionnaires for evaluation of the efficacy of the treatment. The online clinic was designed to facilitate the communication between patients and clinicians and the material was delivered in PowerPoint format through the online platform. All user activities were logged for security purposes.

Results

Statistical analysis showed that this method of delivering psychotherapy significantly reduced patients’ symptoms and also decreased the number of people on the waiting list and increased the amount of compliance in patient's taking part in psychotherapy and number of people who were able to receive psychotherapy.

Conclusion

Despite the proven short and long-term efficacy of psychotherapy, there are some barriers in delivering this treatment. It is an unequivocal public health needs to overcome these barriers through alternative methods of therapy. With Internet use ever rising, developing an online clinic could be a new way in delivering different kinds of psychotherapy.

Stochastic resonance via parametric adaptation: Experiments and numerics

In contrast with the conventionally observed mechanism of stochastic resonance (SR) wherein the level of additive noise is systematically varied with a fixed set-point parameter, in this work we report the emergence of the SR phenomena in an electrochemical system maintaining the same level of noise and varying the parametric distance from a homoclinic bifurcation inherent to the system. The experimental system involves the corrosion of a metal disk in an acidic medium under potentiostatic conditions. The applied potential is used as a control parameter and the anodic current generated during the electrodissolution of the metal is the accessible system variable. In the presence of noise, it was observed that the system was able to enhance its output's fidelity with a weak subthreshold input signal when the set point was kept at an optimal parametric distance from the bifurcation. Numerical simulations were performed on a model for this system to corroborate the experimental observations. This type of SR may be critical in scenarios where a biological entity has control only on its sensory parameters and not on the environmental noise amplitude.

P4535Discharge treatment with ACE inhibitor/ARB after a heart failure hospitalization is associated with a better prognosis irrespectively of left ventricular ejection fraction

Background

Medical therapy could improve the prognosis of real-life patients discharged after a heart failure (HF) hospitalization.

Purpose

We aimed to determine the impact of discharge HF treatment on mortality and readmissions in different left ventricular ejection fraction (LVEF) groups.

Methods

Multicentre prospective registry in 20 Spanish hospitals. Patients were enrolled after a HF hospitalization.

Results

A total of 1831 patients were included (583 [31.8%] HF with reduced ejection fraction [HFrEF]; 227 [12.4%] HF with midrange ejection fraction [HFmrEF]; 610 [33.3%] HF with preserved ejection fraction [HFpEF], and 411 [22.4%] with unknown LVEF. Angiotensin-converting enzyme (ACE) inhibitors/Angiotensin II receptor blockers (ARB) at discharge were independently associated with a reduction in: i) all-cause mortality: hazard ratio (HR) 0.55, 95% confidence interval (CI) 0.41–0.74, P<0.001, with a similar effect in the four groups; ii) mortality due to refractory HF HR 0.45, 95% CI 0.29–0.64, P<0.001, with a similar effect in the three groups with known LVEF; iii) mortality/HF admissions (HR 0.61; 95% CI: 0.50–0.74), more evident in HFrEF (HR 0.54; 95% CI: 0.38–0.78) compared to HRmEF (HR 0.64; 95% CI 0.40–1.02), orHFpEF (HR 0.70; 95% CI 0.53–0.92).Inpatients with HFrEFtriple therapy (ACE inhibitor/ARB+ betablocker+ mineralocorticoid receptor antagonist) was associated with the lowest mortality risk (HR 0.21; 95% CI: 0.08–0.57, P=0.002) compared to patients that received none of these drugs.

Events according to the number of drugs – HFrEF (n=583) 0 (n=14) 1 (n=98) 2 (n=160) 3 (n=294) P Death or heart failure readmissions 10 (71.4) 58 (59.2) 66 (41.3) 106 (36.1) <0.001 All-cause mortality 9 (64.3) 28 (28.6) 31 (19.4) 36 (12.2) <0.001 Mortality due to refractory heart failure 7 (50.0) 14 (14.3) 17 (10.6) 17 (5.8) <0.001 – HFmrEF (n=227) 0 (n=18) 1 (n=57) 2 (n=81) 3 (n=65) P Death or heart failure readmissions 9 (50.0) 35 (61.4) 34 (42.0) 25 (38.5) 0.057 All-cause mortality 5 (27.8) 18 (31.6) 15 (18.5) 11 (16.9) 0.191 Mortality due to refractory heart failure 3 (16.7) 7 (12.3) 7 (8.6) 4 (6.2) 0.475 – HFpEF (n=610) 0 (n=61) 1 (n=242) 2 (n=219) 3 (n=69) P Death or heart failure readmissions 32 (52.5) 97 (40.1) 89 (40.6) 20 (29.0) 0.057 All-cause mortality 20 (32.8) 41 (16.9) 32 (14.6) 10 (14.5) 0.017 Mortality due to refractory heart failure 11 (18.0) 18 (7.4) 13 (5.9) 4 (5.8) 0.041 Outcomes according to the number of medications at discharge.

Kaplan-Meier Curves for study outcomes

Conclusions

Discharge treatment with ACE inhibitor/ARB after a HF hospitalization is associated with a reduction in all-cause and refractory HF mortality, irrespectively of LVEF.

Entrainment of aperiodic and periodic oscillations in the Mercury Beating Heart system using external periodic forcing

We report experimental results indicating entrainment of aperiodic and periodic oscillatory dynamics in the Mercury Beating Heart (MBH) system under the influence of superimposed periodic forcing. Aperiodic oscillations in MBH were controlled to generate stable topological modes, namely, circle, ellipse, and triangle, evolving in a periodic fashion at different parameters of the forcing signal. These periodic dynamics show 1:1 entrainment for circular and elliptical modes, and additionally the controlled system exhibits 1:2 entrainment for elliptical and triangular modes at a different set of parameters. The external periodic forcing of the periodic MBH system reveals the existence of domains of entrainment (1:1, 1:2, 1:3, and 1:4) represented in the Arnold tongue structures. Moreover, Devil's staircase is obtained when the amplitude-frequency space of parameters of the applied signal is scanned.

Molecular Alterations of Nucleocytoplasmic Transport in Patients on the Heart Transplantation Waiting List and Its Correlation With the Severity and Etiology of Heart Failure

OBJECTIVES

To evaluate whether the levels of some molecules implicated in nucleocytoplasmic transport in human cardiomyocytes are related to the severity of heart failure (HF) in patients on the heart transplantation (HT) waiting list, and to determine whether there is a differential pattern of molecular alteration between ischemic cardiomyopathy (ICM) and non-ischemic dilated cardiomyopathy (DCM).

METHODS

Sixty-three blood samples collected before HT were analyzed to identify the levels of IMPORTIN5 (IMP5); IMPORTINalpha2; ATPaseCaTransp (ATPCa); NUCLEOPORIN153kDa (Nup153); NUCLEOPORIN160kDa (Nup160); RANGTPaseAP1 (RanGAP1) and EXPORTIN4 (EXP4). These data were then compared between patients with advanced HF with or without the need for ventricular support with extracorporeal membrane oxygenation (ECMO) as a bridge for HT, as well as between patients with non-ischemic DCM and patients with ICM.

RESULTS

Thirty-three patients had ICM, 26 had non-ischemic DCM, and 4 had heart disease. Seventeen patients required ventricular assistance as a bridge to HT. The levels of ATPCa, RanGAP1, and IMP5 were significantly higher in patients with ECMO, while EXP4 was significantly higher in patients without ECMO. Patients with DCM showed higher levels of IMP5, RanGAP1, and Nup153 than those with ICM.

CONCLUSION

Patients with advanced HF in critical condition (with ECMO as a bridge for HT) presented with significantly higher levels of ATPCa, RanGAP1, and IMP5, while patients with DCM had significantly higher levels of RanGAP1, IMP5, and Nup153. It remains to be clarified whether the determination of these molecules would facilitate the early identification of this group or if their alteration occurs as consequence of circulatory support with ECMO.

Relaxin activates AMPK-AKT signaling and increases glucose uptake by cultured cardiomyocytes

PURPOSE

Many evidences show that the hormone relaxin plays a pivotal role in the physiology and pathology of the cardiovascular system. This pleiotropic hormone exerts regulatory functions through specific receptors in cardiovascular tissues: in experimental animal models it was shown to induce coronary vasodilation, prevent cardiac damage induced by ischemia/reperfusion and revert cardiac hypertrophy and fibrosis. A tight relationship between this hormone and important metabolic pathways has been suggested, but it is at present unknown if relaxin could regulate cardiac metabolism. Our aim was to study the possible effects of relaxin on cardiomyocyte metabolism.

METHODS

Neonatal rat cardiomyocytes were treated with relaxin and (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assays (MTT) were performed to assess metabolic activity; while 2-deoxy-D-[³H] glucose and BODIPY-labelled fatty acid incorporations were analyzed to measure glucose and fatty acid uptakes, and western blot was utilized to study the intracellular signaling pathways activated by the hormone.

RESULTS

We observed that relaxin at 10 ng/ml was able to increase the level of metabolic activity of cultured neonatal rat cardiomyocytes; the rate of 2-deoxy-D-[³H]glucose incorporation demonstrated that relaxin also induced an increase in glucose uptake. First evidence is also offered that relaxin can activate the master energy sensor and regulator AMPK in cardiomyocytes. Moreover, the treatment of cardiomyocytes with relaxin also induced dose-dependent increases in ERK1/2, AKT, and AS160 phosphorylation. That raise in AS160 phosphorylation induced by relaxin was prevented by the pretreatment with AMPK and AKT pathways inhibitors, indicating that both molecules play important roles in the relaxin effects reported.

CONCLUSION

Relaxin can regulate cardiomyocyte metabolism and activate AMPK, the central sensor of energy status that maintains cellular energy homeostasis, and also ERK and AKT, two molecular sensing nodes that coordinate dynamic responses of the cell's metabolic responses.

Age-related periodontitis and alveolar bone loss in rice rats

OBJECTIVE

To characterize in rice rats: (a) periodontitis (PD) progress with feeding of standard laboratory rat chow (STD) during ages 4-80 weeks; and (b) PD progress with feeding of a high sucrose-casein (H-SC) diet during young adulthood.

METHODS

One group (N=12) was euthanized at age 4 weeks (Baseline). Four groups (N=8-16) consumed a STD diet from baseline and were necropsied at ages 22, 30, 52, and 80 weeks. Three groups (N=10-16) consumed an H-SC diet from baseline. Two were necropsied at ages 22 and 30 weeks, respectively. The third switched to the STD diet at age 22 weeks and was necropsied at age 30 weeks. All mandibles/maxillae were assessed by histometry for degree of periodontal inflammation (PD Score), alveolar crest height (ACH, mm), and horizontal alveolar bone height (hABH, mm²).

RESULTS

In STD diet rats aged ≥30 weeks, all endpoints were worse (P<0.05) than at Baseline. In H-SC diet rats aged ≥22 weeks, all endpoints were worse than at Baseline (P<0.05). At age 22 weeks, all endpoints were worse in the H-SC group than in the STD group (P<0.05). By age 30 weeks, the STD and H-SC groups did not differ.

CONCLUSIONS

1) STD diet fed rice rats develop moderate/severe PD by age 30 weeks; 2) an H-SC diet accelerates moderate/severe PD development; and 3) switching to a STD diet does not halt/reverse PD that was accelerated by an H-SC diet. These data further clarify use of the rice rat as a PD model.

Intrinsic periodic and aperiodic stochastic resonance in an electrochemical cell

In this paper we show the interaction of a composite of a periodic or aperiodic signal and intrinsic electrochemical noise with the nonlinear dynamics of an electrochemical cell configured to study the corrosion of iron in an acidic media. The anodic voltage setpoint (V_{0}) in the cell is chosen such that the anodic current (I) exhibits excitable fixed point behavior in the absence of noise. The subthreshold periodic (aperiodic) signal consists of a train of rectangular pulses with a fixed amplitude and width, separated by regular (irregular) time intervals. The irregular time intervals chosen are of deterministic and stochastic origins. The amplitude of the intrinsic internal noise, regulated by the concentration of chloride ions, is then monotonically increased, and the provoked dynamics are analyzed. The signal to noise ratio and the cross-correlation coefficient versus the chloride ions' concentration curves have a unimodal shape indicating the emergence of an intrinsic periodic or aperiodic stochastic resonance. The abscissa for the maxima of these unimodal curves correspond to the optimum value of intrinsic noise where maximum regularity of the invoked dynamics is observed. In the particular case of the intrinsic periodic stochastic resonance, the scanning electron microscope images for the electrode metal surfaces are shown for certain values of chloride ions' concentrations. These images, qualitatively, corroborate the emergence of order as a result of the interaction between the nonlinear dynamics and the composite signal.

Synchronization using environmental coupling in mercury beating heart oscillators

We report synchronization of Mercury Beating Heart (MBH) oscillators using the environmental coupling mechanism. This mechanism involves interaction of the oscillators with a common medium/environment such that the oscillators do not interact among themselves. In the present work, we chose a modified MBH system as the common environment. In the absence of coupling, this modified system does not exhibit self sustained oscillations. It was observed that, as a result of the coupling of the MBH oscillators with this common environment, the electrical and the mechanical activities of both the oscillators synchronized simultaneously. Experimental results indicate the emergence of both lag and the complete synchronization in the MBH oscillators. Simulations of the phase oscillators were carried out in order to better understand the experimental observations.

Polygenic interactions with environmental adversity in the aetiology of major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is a common and disabling condition with well-established heritability and environmental risk factors. Gene-environment interaction studies in MDD have typically investigated candidate genes, though the disorder is known to be highly polygenic. This study aims to test for interaction between polygenic risk and stressful life events (SLEs) or childhood trauma (CT) in the aetiology of MDD.

METHOD

The RADIANT UK sample consists of 1605 MDD cases and 1064 controls with SLE data, and a subset of 240 cases and 272 controls with CT data. Polygenic risk scores (PRS) were constructed using results from a mega-analysis on MDD by the Psychiatric Genomics Consortium. PRS and environmental factors were tested for association with case/control status and for interaction between them.

RESULTS

PRS significantly predicted depression, explaining 1.1% of variance in phenotype (p = 1.9 × 10(-6)). SLEs and CT were also associated with MDD status (p = 2.19 × 10(-4) and p = 5.12 × 10(-20), respectively). No interactions were found between PRS and SLEs. Significant PRSxCT interactions were found (p = 0.002), but showed an inverse association with MDD status, as cases who experienced more severe CT tended to have a lower PRS than other cases or controls. This relationship between PRS and CT was not observed in independent replication samples.

CONCLUSIONS

CT is a strong risk factor for MDD but may have greater effect in individuals with lower genetic liability for the disorder. Including environmental risk along with genetics is important in studying the aetiology of MDD and PRS provide a useful approach to investigating gene-environment interactions in complex traits.

Resistance index determination in the pre and post kidney transplantation time points in graft dysfunction diagnosis

BACKGROUND

Donor shortage necessitates the development of tools capable of objectively assessing kidney graft quality from expanded criteria donors and kidneys donated after cardiac death. The deteriorating donor profile is leading to a shift from cold storage toward machine perfusion preservation. Several authors found that renal resistance (RR) at the end of machine perfusion was an independent risk factor for the development of delayed graft function (DGF). In contrast, Doppler ultrasonography in the posttransplant period reveals renal hemodynamics and is useful in diagnosing renal allograft dysfunction. We sought to determine concordance between RR and the resistance index (RI) and their diagnostic value in the assessment of graft viability.

METHODS

RR was determined at the end of perfusion during hypothermic machine preservation and RI was measured by Doppler ultrasonography in the early posttransplant period. Agreement between these 2 measures was established by means of the intraclass correlation coefficient (ICC). Diagnostic validity for RR and RI was determined by sensitivity, specificity and positive and negative predictive values.

RESULTS

The ICC was 0.135, which indicates a slight agreement. RR and RI had limited value in the prediction of DGF for a specific kidney as reflected by a c-statistic of 0.58 and 0.66, respectively.

CONCLUSIONS

There is no agreement between the RR and RI, which may be owing to the different conditions under which measurements are made. The poor predictive power of RR for DGF indicates that kidneys should not be discarded based on RR criteria alone.

Training and capacity building evaluation: Maximizing resources and results with Success Case Method

This article describes the use of Success Case Method (Brinkerhoff, 2003) to evaluate health promotion and public health training programs. The goal of the Office Community Research and Engagement (OCRE) of the Puerto Rico Clinical and Translational Research Consortium (PRCTRC) is to establish a stable and sustainable translational research capacity. Early efforts toward achieving this goal included sponsoring two independent research training programs. A description of the implementation of the five step Success Case Method is presented. Results reveal that SCM would deem both trainings as highly successful, based upon the overall impact of a low number of success cases. However, a traditional summative evaluation would consider this disappointing. Strengths of SCM are discussed. It was concluded that the Success Case Method is a useful and valuable evaluative method for measuring the success of health promotion and public health training initiatives and provides sufficient information for decision-making processes.

Efficacy of mesalazine or beclomethasone dipropionate enema or their combination in patients with distal active ulcerative colitis

OBJECTIVE

Mesalazine or Beclomethasone dipropionate (BDP) enema have been shown effective in treatment of distal active ulcerative colitis (UC). This study was aimed to determine whether the combination of topical mesalazine and BDP is superior to topical mesalazine or BDP used alone in patients with distal active UC. PATIENTS AND METHODS: One-hundred and twenty patients with clinical, endoscopic and histological diagnosis of distal active UC were randomly assigned to a regimen with mesalazine tablets 2.4 g/day associated to either mesalazine enema 4 g/day (group A, n=40), BDP 3 mg/60 ml every day (group B, n=40) or the combination treatment with the two compounds in a single administration (group C, n=40) for eight weeks. After four weeks of treatment all patients underwent clinical controls but only 109 patients returned back for clinical, endoscopic and histological controls at the end of the treatment period.

RESULTS

After eight weeks, complete remission rates were of 52%, 47% and 65% respectively, in group A, B and C. From baseline to 4 and 8 weeks the CAI score decreased significantly in all the three groups (p < 0.0001).

CONCLUSIONS

All the three combinations achieved equivalent results in terms of symptoms in inducing symptoms relief and mucosa healing in distally active UC.

Familiality and SNP heritability of age at onset and episodicity in major depressive disorder

BACKGROUND

Strategies to dissect phenotypic and genetic heterogeneity of major depressive disorder (MDD) have mainly relied on subphenotypes, such as age at onset (AAO) and recurrence/episodicity. Yet, evidence on whether these subphenotypes are familial or heritable is scarce. The aims of this study are to investigate the familiality of AAO and episode frequency in MDD and to assess the proportion of their variance explained by common single nucleotide polymorphisms (SNP heritability).

METHOD

For investigating familiality, we used 691 families with 2-5 full siblings with recurrent MDD from the DeNt study. We fitted (square root) AAO and episode count in a linear and a negative binomial mixed model, respectively, with family as random effect and adjusting for sex, age and center. The strength of familiality was assessed with intraclass correlation coefficients (ICC). For estimating SNP heritabilities, we used 3468 unrelated MDD cases from the RADIANT and GSK Munich studies. After similarly adjusting for covariates, derived residuals were used with the GREML method in GCTA (genome-wide complex trait analysis) software.

RESULTS

Significant familial clustering was found for both AAO (ICC = 0.28) and episodicity (ICC = 0.07). We calculated from respective ICC estimates the maximal additive heritability of AAO (0.56) and episodicity (0.15). SNP heritability of AAO was 0.17 (p = 0.04); analysis was underpowered for calculating SNP heritability of episodicity.

CONCLUSIONS

AAO and episodicity aggregate in families to a moderate and small degree, respectively. AAO is under stronger additive genetic control than episodicity. Larger samples are needed to calculate the SNP heritability of episodicity. The described statistical framework could be useful in future analyses.

Kuramoto transition in an ensemble of mercury beating heart systems

We have studied, experimentally, the collective behavior of the electrically coupled autonomous Mercury Beating Heart (MBH) systems exhibiting the breathing mode, by varying both the coupling strength and the population size (from N = 3 to N = 16). For a fixed N, the electrical and the mechanical activities of the MBH systems achieve complete synchronization at different coupling strengths. The electrical activity of each MBH system is measured by the corresponding electrode potential (Ei = Vi). Additionally, the mechanical activity of each MBH oscillator is visually observed (snapshots and video clips). Subsequently, this activity is quantified by calculating the temporal variation in the area (Ai) of the Hg drop. As a result, the synchronization of the electrical (Ei = Vi) and the mechanical (Ai) activities can be measured. The extent of synchronization was quantified by employing the order parameter (r). Our experimental results are found to be in agreement with the Kuramoto theory.