Using marginal structural joint models to estimate the effect of a time-varying treatment on recurrent events and survival: An application on arrhythmogenic cardiomyopathy

In many clinical applications to evaluate the effect of a treatment, randomized control trials are difficult to carry out. On the other hand, clinical observational registries are often available and they contain longitudinal data regarding clinical parameters, drug therapies, and outcomes. In the past, much research has addressed causal methods to estimate treatment effects from observational studies. In the context of time-varying treatments, marginal structural models are often used. However, most analyses have focused on binary outcomes or time-to-the-first event analyses. The novelty of our approach is to combine the marginal structural methodology with the case where correlated recurrent events and survival are the outcomes of interest. Our work focuses on solving the nontrivial problem of defining the measures of effect, specifying the model for the time-dependent weights and the model to estimate the outcome, implementing them, and finally estimating the final treatment effects in this life-history setting. Our approach provides a strategy that allows obtaining treatment effect estimates both on the recurrent events and the survival with a clear causal and clinical interpretation. At the same time, the strategy we propose is based on flexible modeling choices such as the use of joint models to capture the correlation within events from the same subject and the specification of time-dependent treatment effects. The clinical problem which motivated our work is the evaluation of the treatment effect of beta-blockers in arrhythmogenic right ventricular cardiomyopathy (ARVC/D), and the dataset comes from the Trieste Heart Muscle Disease Registry.

P295 EXERCISE OXYGEN KINETIC IN HYPERTROPHIC CARDIOMYOPATHY: RESULTS FROM A MULTICENTER CARDIOPULMONARY EXERCISE TESTING STUDY

Aims

Reduced cardiac output (CO) has been considered crucial in symptoms’ genesis in hypertrophic cardiomyopathy (HCM). We evaluated the cardiopulmonary exercise testing (CPET) response in HCM focusing on parameters strongly associated with stroke volume (SV) and cardiac output (CO), such as oxygen uptake (VO2) and O2–pulse, considering both their absolute values and temporal behavior during physical exercise.

Methods and Results

We enrolled 312 non–end stage HCM patients, divided according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva maneuver (72% with LVOTO<30; 10% between 30 and 49 and 18% ≥ 50mmHg). Peak VO2 (percent of predicted), O2–pulse and ventilation to carbon dioxide production (VE/VCO2) slope did not change across LVOTO groups. Ninety–six (31%) HCM patients presented an abnormal O2–pulse temporal behavior, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106±45 vs. 130±49W), VO2 (74±17 vs. 80±20%) and O2–pulse (12 [9–14] vs. 14 [11–17]ml/beat), with higher VE/VCO2 slope (28 [25–31] vs. 27 [24–31]) (p < 0.005 for all). Only 2 patients had an abnormal VO2/work slope.

Conclusion

None of CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal O2–pulse exercise behavior, which is strongly related to inadequate SV during exercise, correlates with reduced functional capacity (peak and anaerobic threshold VO2 and workload) and increased VE/VCO2 slope, helping identifying more advanced disease irrespectively of LVOTO. Adding O2–pulse kinetics evaluation to standard CPET could lead to a potential incremental benefit in terms of HCM prognostic stratification and, then, therapeutic management.

Exercise oxygen pulse kinetics in patients with hypertrophic cardiomyopathy

OBJECTIVES

Reduced cardiac output (CO) has been considered crucial in symptoms' genesis in hypertrophic cardiomyopathy (HCM). Absolute value and temporal behaviour of O₂-pulse (oxygen uptake/heart rate (VO₂/HR)), and the VO₂/work relationship during exercise reflect closely stroke volume (SV) and CO changes, respectively. We hypothesise that adding O₂-pulse absolute value and kinetics, and VO₂/work relationship to standard cardiopulmonary exercise testing (CPET) could help identify more exercise-limited patients with HCM.

METHODS

CPETs were performed in 3 HCM dedicated clinical units. We retrospectively enrolled non-end-stage consecutive patients with HCM, grouped according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva manoeuvre (72% of patients with LVOTO <30; 10% between 30 and 49 and 18% ≥50 mm Hg). We evaluated the CPET response in HCM focusing on parameters strongly associated with SV and CO, such as O₂-pulse and VO₂, respectively, considering their absolute values and temporal behaviour during exercise.

RESULTS

We included 312 patients (70% males, age 49±18 years). Peak VO₂ (percentage of predicted), O₂-pulse and ventilation to carbon dioxide production (VE/VCO₂) slope did not change across LVOTO groups. Ninety-six (31%) patients with HCM presented an abnormal O₂-pulse temporal behaviour, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106±45 vs 130±49 W), VO₂ (21.3±6.6 vs 24.1±7.7 mL/min/kg; 74%±17% vs 80%±20%) and O₂-pulse (12 (9-14) vs 14 (11-17) mL/beat), with higher VE/VCO₂ slope (28 (25-31) vs 27 (24-31)) (p<0.005 for all). Only 2 patients had an abnormal VO₂/work slope.

CONCLUSION

None of the frequently used CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal temporal behaviour of O₂-pulse during exercise, which is strongly related to inadequate SV increase, correlates with reduced functional capacity (peak and anaerobic threshold VO₂ and workload) and increased VE/VCO₂ slope, identifying more advanced disease irrespectively of LVOTO.

423 Prevalence and prognostic significance of atrial arrhythmias in arrhythmogenic cardiomyopathy

Aims

Limited data are available concerning atrial arrhythmias (AA) role in arrhythmogenic cardiomyopathy (AC). The aim of the present study was to assess the prevalence and incidence of AA in a large cohort of AC patients and to evaluate its association with clinical outcomes.

Methods and results

We retrospectively analysed 115 patients with definite diagnosis of ARVC, according to 2010 Task Force Criteria, enrolled in the Trieste Heart Muscle Disease Registry. Subjects were further classified into two phenotypic variants, based on ventricular involvement: right-dominant and biventricular form. Uni- and multivariable, extended Kaplan-Meier and cumulative incidence function analysis were performed, as appropriate, for the primary composite endpoint of death and heart transplant (HTx) and for the two distinct secondary endpoints of: (i) death, HTx and first heart failure (HF) hospitalization; (ii) first major ventricular arrhythmias (MVA). Mean age of patients at the time of enrollment was 39 ± 16 years and 80% were male. 73 patients (63%) had a right-dominant form, while 42 (37%) presented a biventricular involvement. AA occurred in the 26% of our study population at baseline or during a median follow-up of 214 months (IQR: 105–311), with a non-significant trend in higher cumulative incidence of AA in patients with biventricular form. At baseline, patients experiencing AA were older (44 ± 18 vs. 37 ± 15 years, P = 0.044) and had larger atrial dimensions, in particular of the right atrium (RA) (23, IQR: 19–27 vs. 18, IQR: 15–25 cm2, P &lt; 0.007). AA emerged as independently associated to death/HTx (HR 2.68, 95% CI: 1.02–7.05, P = 0.046) along with NYHA class &gt;2 (HR: 7.08, 95% CI: 2.50–20.1, P &lt; 0.001) and RA area (HR: 1.05, 95% CI: 1.01–1.09, P = 0.011). Consistently, AA were also independently associated with the secondary endpoint of death/HTx/HF hospitalization (HR: 2.50, 95% CI: 1.06–5.88, P = 0.036), together with NYHA &gt;2, the presence of biventricular involvement, higher RA and left atrium area. Finally, AA did not emerge as independently correlated to MVA during follow-up.

Conclusions

This observational long-term study suggests that AA were common in patients with AC and were independently associated with poor outcomes, mostly related to HF events. A prompt identification throughout the follow-up of AA appears relevant in improving the clinical management of AC patients.

53 Exercise oxygen kinetic in hypertrophic cardiomyopathy: results from a multicentre cardiopulmonary exercise testing study

Aims

Reduced cardiac output (CO) has been considered crucial in symptoms’ genesis in hypertrophic cardiomyopathy (HCM). We evaluated the cardiopulmonary exercise testing (CPET) response in HCM focusing on parameters strongly associated with stroke volume (SV) and cardiac output (CO), such as oxygen uptake (VO2) and O2-pulse, considering both their absolute values and temporal behaviour during physical exercise.

Methods and results

We enrolled 312 non-end stage HCM patients, divided according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva manoeuver (72% with LVOTO &lt; 30; 10% between 30 and 49; and 18% ≥50 mmHg). Peak VO2 (percent of predicted), O2-pulse, and ventilation to carbon dioxide production (VE/VCO2) slope did not change across LVOTO groups. Ninety-six (31%) HCM patients presented an abnormal O2-pulse temporal behaviour, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106 ± 45 vs. 130 ± 49 W), VO2 (74 ± 17% vs. 80 ± 20%) and O2-pulse (12 [9–14] vs. 14 [11–17]ml/beat), with higher VE/VCO2 slope (28 [25–31] vs. 27 [24–31]) (P &lt; 0.005 for all). Only two patients had an abnormal VO2/work slope.

Conclusions

None of CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal O2-pulse exercise behaviour, which is strongly related to inadequate SV during exercise, correlates with reduced functional capacity (peak and anaerobic threshold VO2 and workload) and increased VE/VCO2 slope, helping identifying more advanced disease irrespectively of LVOTO. Adding O2-pulse kinetics evaluation to standard CPET could lead to a potential incremental benefit in terms of HCM prognostic stratification and, then, therapeutic management.

[Hyperkalemia in heart failure: etiology, epidemiology and prognosis]

Hyperkalemia (HK) is a common condition among heart failure (HF) patients, either due to their comorbidities, such as chronic renal failure, or due to the administration of therapies capable of promoting an increase in serum potassium (K+), such as renin-angiotensin-aldosterone system inhibitors (RAASi). RAASi are among the most important treatments for HF, especially in patients with reduced ejection fraction. This class of drugs, acting on the neurohormonal mechanisms, that lead to the worsening of hemodynamic compensation, has shown to improve the prognosis of HF patients, both in terms of mortality and HF hospitalizations. HK is a major cause of dose reduction, or even discontinuation, of RAASi, thus, indirectly worsening HF patient's prognosis. Pharmacological strategies for HK treatment in outpatients have long been based solely on therapies of dubious efficacy, such as sodium polystyrene sulfonate, which are difficult to administer in an extended period of time. Reasonably, the use of the new K+ binders (patiromer and sodium zirconium cyclosilicate) in clinical practice, allowing to reduce serum K+ levels without discontinuing RAASi therapy, will improve the prognosis of patients with HK and HF.

Comparison between PtCO2 and PaCO2 and Derived Parameters in Heart Failure Patients during Exercise: A Preliminary Study

Evaluation of arterial carbon dioxide pressure (PaCO2) and dead space to tidal volume ratio (VD/VT) during exercise is important for the identification of exercise limitation causes in heart failure (HF). However, repeated sampling of arterial or arterialized ear lobe capillary blood may be clumsy. The aim of our study was to estimate PaCO2 by means of a non-invasive technique, transcutaneous PCO2 (PtCO2), and to verify the correlation between PtCO2 and PaCO2 and between their derived parameters, such as VD/VT, during exercise in HF patients. 29 cardiopulmonary exercise tests (CPET) performed on a bike with a ramp protocol aimed at achieving maximal effort in ≈10 min were analyzed. PaCO2 and PtCO2 values were collected at rest and every 2 min during active pedaling. The uncertainty of PCO2 and VD/VT measurements were determined by analyzing the error between the two methods. The accuracy of PtCO2 measurements vs. PaCO2 decreases towards the end of exercise. Therefore, a correction to PtCO2 that keeps into account the time of the measurement was implemented with a multiple regression model. PtCO2 and VD/VT changes at 6, 8 and 10 min vs. 2 min data were evaluated before and after PtCO2 correction. PtCO2 overestimates PaCO2 for high timestamps (median error 2.45, IQR -0.635-5.405, at 10 min vs. 2 min, p-value = 0.011), while the error is negligible after correction (median error 0.50, IQR = -2.21-3.19, p-value > 0.05). The correction allows removing differences also in PCO2 and VD/VT changes. In HF patients PtCO2 is a reliable PaCO2 estimation at rest and at low exercise intensity. At high exercise intensity the overall response appears delayed but reproducible and the error can be overcome by mathematical modeling allowing an accurate estimation by PtCO2 of PaCO2 and VD/VT.

Introducing the Front-Of-Pack Acceptance Model: the role of usefulness and ease of use in European consumers' acceptance of Front-Of-Pack Labels

In recent years, increasing attention to the utilisation of Front-Of-Pack Labels (FOPLs) as a tool to prompt individuals towards healthier food choices has been observed both in regulatory bodies and academic research. However, few theoretical models have been used to understand their role in consumer decision-making, as well as the antecedents that induce individuals to accept the information provided by the label, and to benchmark FOPL performance in different markets.Through a sequence of two studies conducted in Italy, France and the UK on 2812 primary grocery shoppers, we developed a new theoretical framework, the Front-Of-Pack Acceptance Model, applicable both in contexts in which FOPL are present, and in which they should be introduced. Our findings suggest a structural link between the usefulness and ease of use of the labels and the way consumers form their attitudes and intentions towards buying healthier products.

Interpretability of time-series deep learning models: A study in cardiovascular patients admitted to Intensive care unit

Interpretability is fundamental in healthcare problems and the lack of it in deep learning models is currently the major barrier in the usage of such powerful algorithms in the field. The study describes the implementation of an attention layer for Long Short-Term Memory (LSTM) neural network that provides a useful picture on the influence of the several input variables included in the model. A cohort of 10,616 patients with cardiovascular diseases is selected from the MIMIC III dataset, an openly available database of electronic health records (EHRs) including all patients admitted to an ICU at Boston's Medical Centre. For each patient, we consider a 10-length sequence of 1-hour windows in which 48 clinical parameters are extracted to predict the occurrence of death in the next 7 days. Inspired from the recent developments in the field of attention mechanisms for sequential data, we implement a recurrent neural network with LSTM cells incorporating an attention mechanism to identify features driving model's decisions over time. The performance of the LSTM model, measured in terms of AUC, is 0.790 (SD = 0.015). Regard our primary objective, i.e. model interpretability, we investigate the role of attention weights. We find good correspondence with driving predictors of a transparent model (r = 0.611, 95% CI [0.395, 0.763]). Moreover, most influential features identified at the cohort-level emerge as known risk factors in the clinical context. Despite the limitations of study dataset, this work brings further evidence of the potential of attention mechanisms in making deep learning model more interpretable and suggests the application of this strategy for the sequential analysis of EHRs.

Antiarrhythmic therapy and risk of cumulative ventricular arrhythmias in arrhythmogenic right ventricle cardiomyopathy

OBJECTIVES

The aim of our study was to investigate the benefit of antiarrhythmic drugs (AAD) - beta-blockers, sotalol or amiodarone - in a cohort of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) patients with long-term longitudinal follow up.

BACKGROUND

AAD are prescribed in ARVC to prevent ventricular arrhythmias and control symptoms. However, there are no controlled clinical trials and knowledges regarding the efficacy of AAD in ARVC are limited.

METHODS

The study population included 123 patients with definite diagnosis of ARVC and ≥ 2 clinical evaluations. The primary outcome was a composite of sudden cardiac death (SCD)/recurrent major ventricular arrythmias (MVA): sudden cardiac arrest, sustained ventricular tachycardia (VT) and appropriate implantable cardioverter defibrillator interventions, including recurrent events in patients with >1 MVA. Time to first event (SCD or MVA) was considered as secondary composite endpoint.

RESULTS

Sixteen patients were taking AAD at baseline and 75 started at least one AAD during a median follow-up of 132 months [61-255]. A total of 37 patients experienced ≥1 MVA with a total count of 83 recurrent MVA. After adoption of a propensity score analysis, no AAD were associated with lower risk of recurrent MVA. However, if dosage of AAD was considered, beta-blockers at >50% target dose were associated with a significant reduction in the risk of MVA compared to patients not taking beta-blockers (HR 0.10, 95% CI 0.02-0.46, p = 0.004).

CONCLUSIONS

In a large cohort of ARVC patients with a long-term follow-up, only beta-blockers administrated at >50% target dose were associated with lower risk of SCD/recurrent MVA.

A cross-country experimental study on consumers' subjective understanding and liking on front-of-pack nutrition labels

Different Front-of-Pack (FOP) nutritional labels have been implemented in order to increase consumers' awareness of food nutritional quality and encourage healthier choices. However, few studies have analysed the effects of FOPLs on consumers' subjective understanding and liking across different socio-cultural contexts. This study tests the effect that the new enriched informative label NutrInform Battery and the summary label Nutri-Score have on subjective comprehension and liking across 2776 respondents of seven European countries (France, Germany, Greece, Italy, Portugal, Romania and Spain). Main effects regarding socio-demographic differences are also explored according to extant literature and highlighting significant effects of education and income. This study therefore extends the current research on subjective understanding and liking with a cross-country analysis. Findings suggest that NutrInform Battery can help consumers in understanding information in a relevant way, obtaining the highest performance across countries and showing limited impact of socio-cultural differences.

Modifications to mobile chest radiography technique during the COVID-19 pandemic - implications of X-raying through side room windows

INTRODUCTION

Modifications to common radiographic techniques have resulted from the challenges presented by the COVID-19 pandemic. Reports exist regarding the potential benefits of undertaking mobile radiography through side room windows. The aim of this study was to evaluate the impact on image quality and exposure factors when undertaking such examinations.

METHODS

A phantom based study was undertaken using a digital X-ray room. Control acquisitions, using a commercially available image quality test tool, were performed using standard mobile chest radiography acquisition factors. Image quality (physical and visual), incidence surface air kerma (ISAK), Exposure Index (EI) and Deviation Index (DI) were recorded. Image quality and radiation dose were further assessed for two additional (experimental) scenarios, where a side room window was located immediately adjacent to the exit port of the light beam diaphragm. The goal of experimental scenario one was to modify exposure factors to maintain the control ISAK. The goal of experimental scenario two was to modify exposure factors to maintain the control EI and DI. Dose and image quality data were compared between the three scenarios.

RESULTS

To maintain the pre-window (control) ISAK (76 μGy), tube output needed a three-fold increase (90 kV/4 mAs versus 90 kV/11.25 mAs). To maintain EI/DI a more modest increase in tube output was required (90 kV/8 mAs/ISAK 54 μGy). Physical and visual assessments of spatial resolution and signal-to-noise ratio were indifferent between the three scenarios. There was a slight statistically significant reduction in contrast-to-noise ratio when imaging through the glass window (2.3 versus 1.4 and 1.2; P = 0.005).

CONCLUSION

Undertaking mobile X-ray examinations through side room windows is potentially feasible but does require an increase in tube output and is likely to be limited by minor reductions in image quality.

IMPLICATIONS FOR PRACTICE

Mobile examinations performed through side room windows should only be used in limited circumstances and future clinical evaluation of this technique is warranted.

Focus on arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy is a myocardial disease generally caused by desmosomal mutations and characterized by progressive replacement of cardiomyocites with fibro-adipose tissue. In the classic form of the disease right ventricle is predominantly affected. However, biventricular and left-dominant variants have been recently recognized, leading to the new nosological definition of arrhythmogenic cardiomyopathy. The condition affects mostly young adults and athletes and is clinically characterized by ventricular arrhythmias, heart failure and sudden cardiac death. The diagnosis is based on clinical-instrumental criteria, including family history, morpho-functional and electrocardiographic abnormalities, ventricular arrhythmias and genetic defects (Task Force Criteria, 2010). The main goal in the management of patients is the prevention of sudden cardiac death, where implantable cardioverter-defibrillator is the only effective therapeutic strategy. Many arrhythmic risk factors have been described. Recently, an on-line calculator has been proposed, but it needs further validation.

Comparison of different prediction models for the indication of implanted cardioverter defibrillator in patients with arrhythmogenic right ventricular cardiomyopathy

Aims

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with a high risk of sudden cardiac death. Three different prediction models for the indication of implanted cardioverter defibrillator (ICD) are now available: the 5 year ARVC risk score, the International Task Force Consensus (ITFC) criteria, and the Heart Rhythm Society (HRS) criteria. We compared these three prediction models in a validation cohort of patients with definite ARVC.

Methods and results

In a cohort of 140 patients with definite ARVC, the 5 year ARVC risk score and the ITFC and HRS criteria were compared for the prediction of a major combined endpoint of sudden cardiac death, appropriate ICD intervention, resuscitated cardiac arrest, and sustained ventricular tachycardia. During the follow‐up, 65 major events occurred. The 5 year ARVC risk score with a threshold >10%, derived from the maximally selected rank statistic, predicted 62 (95%) events [odds ratio (OR) 9.1, 95% confidence interval (CI) 2.6–32, P = 0.0006], the ITFC criteria 53 (81%, OR 4.8, 95% CI 2.2–10.3, P = 0.0001), and the HRS criteria 29 (45%, OR 4.2, 95% CI 1.9–9.3, P = 0.0003). At the analysis of decision curve for ICD implantation, a 5 year ARVC risk score >10% showed a greater net benefit than the ITFC and HRS criteria over a wide range of threshold probability of events. Finally, at multivariate analysis, the 5 year ARVC risk score >10% was the only independent predictor of major events.

Conclusions

The 5 year score with a threshold of >10% was more effective for predicting events than the ITFC and HRS criteria.

Psychological Underpinnings of Brands

Research in psychology has shown that even routinely experienced everyday objects such as brands can trigger cognitively engaging, emotional, and socially meaningful experiences. In this article, we review three key areas where current advances reside: brands as passive objects with utilitarian and symbolic meanings, brands as relationship partners and regulators of personal relationships, and brands as creators of social identity with social group linking value. Research in these areas is grounded in a number of fundamental perspectives within cognitive, emotional, motivational, personality, interpersonal, and group psychology. We conclude by addressing emerging areas for research.

Effects on consumers' subjective understanding of a new front-of-pack nutritional label: a study on Italian consumers

Front-of-pack nutritional label (FOPL) systems have been developed worldwide to amplify and simplify nutritional information and induce healthier choices. This study explores consumers' internal reactions - in terms of subjective understanding and liking - to a new FOPL: the NutrInform Battery. The investigation aims to assess the clear comprehension by consumers of the information provided by the NutrInform Battery FOPL scheme, based on a sample of 200 Italian respondents, in a real-life setting, with products representative of the most widely consumed food categories, using a between-subject design. Participants were randomly assigned to one of the two conditions: products marked with NutrInform Battery or Nutri-Score labels. The results provided evidence of the effectiveness of NutrInform Battery in being perceived by consumers as an informative FOPL scheme. Specifically, consumers found NutrInform Battery more informative and helpful than Nutri-Score in terms of their understanding of the product composition.

[Hyperkalemia in heart failure: new solutions for an old problem]

Potassium is the main intracellular ion and its homeostasis is finely regulated by the renal and gastrointestinal tract. Renal failure and hyperkalemia are conditions commonly found in patients with heart failure, the result of a complex interaction between heart and kidney (e.g. cardio-renal syndrome) and the side effects of drugs commonly used for treating heart disease (e.g. renin-angiotensin-aldosterone system inhibitors). Although hyperkalemia increases the risk of heart conduction disorders and life-threatening arrhythmias, its prognostic significance in heart failure is uncertain. Hyperkalemia and progression of renal damage are the main limitations to the introduction and titration of heart failure therapies. New drugs for the prevention and chronic treatment of hyperkalemia allow the introduction and modulation of anti-neurohormonal therapies in patients with heart failure otherwise excluded from these treatments due to excessively high serum potassium levels.This review illustrates the pathophysiological, epidemiological and prognostic aspects of hyperkalemia and analyses the possible treatments for this condition in heart failure patients.

Automated Synthesis of 68Ga-DOTA-TOC with a Cationic Purification System: Evaluation of Methodological and Technical Aspects in Routine Preparations

BACKGROUND AND OBJECTIVE

Gallium-68 is a PET isotope available in each nuclear medicine departments, even those not equipped with a cyclotron, since it is easily obtained by eluting compact and transportable generator system. The preparation of Ga-68 DOTA-labeled compounds is performed by remotely controlled automated systems developed in order to ensure production efficiency, reproducibility of the results, fast reaction time, to facilitate the synthesis and minimize the radiation exposure. Many automatic synthesis systems are available on the radiopharmaceutical market, however, they requires some technical adaptations for routine use. We reported the [68Ga]Ga-DOTA-TOC production by automated cassette-based theranostic synthesizer system used in combination with a disposable GMP grade cassette system for cationic purification.

METHODS

The synthesizer is integrated with the 68Ge/68Ga generator systems and it allows to perform elution, eluate purification and radiolabeling in about 38 minutes. We have performed in 2 year (January 2016 - January 2018) over 100 [68Ga]Ga-DOTA-TOC preparations.

RESULTS

The average synthesis yield of radiopharmaceutical production was 54.4 ± 2.3 % and the radiochemical purity average was found 96.94 ± 0.74 %. Only three [68Ga]Ga-DOTA-TOC preparations have failed.

CONCLUSION

The methodology and the adopted technical solutions allowed to obtain a high quality radiopharmaceutical product as required by the European Pharmacopoeia.

Differential expression of innate immune response genes in clinical phases of chronic hepatitis B infection

We investigated innate immune gene expression in clinical phases of chronic hepatitis B infection, including immune tolerant (IT), immune active (IA), inactive carrier (IC) and hepatitis B e antigen (HBeAg)-negative phases, as well as healthy controls. Expression levels of interferon types I, II and III, their receptor subunits, IRFs, TLRs and other IFN-induced genes in peripheral blood mononuclear cells were compared. Forty HBsAg-positive treatment-naïve subjects without co-infection with HIV, HCV or HDV were enrolled. To complement the viral load, the expression levels of 37 innate immune genes were measured by qPCR. The highest response of the innate immune system was observed in the IT and HBeAg-negative phases, and the IC phase had the lowest response; 31 of the 37 studied genes reached their maximum mRNA expression levels in the IT and HBeAg-negative phases, and the minimum expression levels of 23 genes were found in the IC phase. The highest mRNA expression levels of IFNs, IFN receptor subunits, IRFs and TLRs genes in all clinical phases were IFN-λ2 and 3, IFN-γR2, IRF7 and TLR7, and the lowest levels of mRNA expression were observed for IFN-α, IFN-λR1, IRF8 and TLR2. We conclude that innate immune response genes are expressed differentially among chronic HBV phases, and this difference may help to develop new precise and noninvasive methods to determine the progression of disease in chronic HBV patients.

Chronic obstructive pulmonary disease (COPD) exacerbation: impact of comorbidities on length and costs during hospitalization

OBJECTIVE

A retrospective cohort study was performed, using administrative database of the Local Health Unit Roma-A (LHU RM-A). The included subjects were residing in one of the four districts and were hospitalized for COPD exacerbation in healthcare facilities of the LHU during years 2010-2012.

PATIENTS AND METHODS

The aim of the present study is to evaluate the impact of comorbidities, length and costs of hospital stay in patients with COPD exacerbations. Chronic obstructive pulmonary disease (COPD) is often associated with other diseases (cardiovascular diseases, diabetes, metabolic syndrome, chronic renal failure, depression) that can increase risk of mortality and hospitalization.

RESULTS

A total of 1890 COPD patients are included in the study. The mean length of hospitalization is 12.25 days (SD ± 10.91), 11.63 days (SD ± 9.76) and 11.91 days (SD ± 9.69) with a mean cost of hospitalization amounting to euro 3683.48 (SD ± 2037.12), 3356.82 (SD ± 1674.86) and 3706.81 (SD ± 2087.72) in 2010, 2011 and 2012 respectively. The presence and number of comorbidities are positively and significantly associated to the length and cost of hospitalization. In particular, patients with cardiovascular diseases or diabetes mellitus associated with other comorbidities present the highest values of hospital stay and cost. The cost and the length of hospitalization were significantly linked to the number of comorbidities.

CONCLUSIONS

Comorbidities play an important role in the hospital management of COPD exacerbation, increasing health care costs related to this disease.

Early use of non invasive ventilation in patients with amyotrophic lateral sclerosis: what benefits?

OBJECTIVE

The aim of this study was to analyze the efficacy of an early start of NIV in ALS patients, evaluating respiratory and ventilatory parameters.

PATIENTS AND METHODS

Functional respiratory parameters and arterial blood gas analysis were evaluated in forty-six patients. All patients were informed about the benefits and possible adverse effects of therapeutic support with NIV and divided in two groups based on the compliance to early start therapy with NIV (Group A) or not (Group B).

RESULTS

Among 46 ALS patients consecutively visited in our Unit, we included 20 patients in the Group A and 16 in the Group B. We have emphasized the importance of the early use of NIV stressing the difference between two groups analyzed, particularly in terms of pulmonary function tests and arterial blood gas analysis. Significant correlation was observed between Vital Capacity (VC), Forced Expiratory volume in one second (FEV1), and maximal inspiratory pressures (PImax).

CONCLUSIONS

Our study highlights the importance of noninvasive mechanical ventilation as a treatment for ALS patients and also shows the early start of NIV as an important approach in order to postpone the functional decline and the decrease of respiratory muscle strength.

Atrial fibrillation in the acute, hypercapnic exacerbations of COPD

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) has been associated with a high frequency of arrhythmias. Atrial fibrillation (AF) is one of the most common arrhythmias and causes substantial morbidity and mortality. Emerging risk factors for the development of AF include a variety of breathing disorders like COPD. Few studies have analyzed the role of reduced lung function and respiratory acidosis in predicting AF. Aim of the current study was to investigate the role of hypercapnia, pulmonary systolic hypertension and lung function impairment in COPD patients, as risk factors for atrial fibrillation development.

PATIENTS ANDV METHODS

We evaluated a population of individuals consecutively hospitalized for COPD exacerbation and hypercapnic respiratory failure between January 2012 and January 2013; among them we selected a subgroup of patients presenting a paroxysmal episode of atrial fibrillation. All patients underwent pulmonary function tests, haemogasanalysis, electrocardiogram and transthoracic echocardiography.

RESULTS

Among the 193 subjects evaluated, 35 individuals with AF and COPD were enrolled in the study. Risk of new AF was higher in those subjects with lower FEV1 and higher PaCO2 values, also there was a significantly increased prevalence of AF in patients with higher value of Pulmonary Artery Systolic Pressure (PASP), obtained by transthoracic echocardiography. Linear correlation between variables revealed a direct relationships between hypercapnia and PASP and left and right atrial areas.

CONCLUSIONS

Impaired pulmonary function, hypercapnia and high values of PASP are independent predictors of incident AF.

Covert brand recognition engages emotion-specific brain networks

Consumer goods' brands have become a major driver of consumers' choice: they have got symbolic, relational and even social properties that add substantial cultural and affective value to goods and services. Therefore, measuring the role of brands in consumers' cognitive and affective processes would be very helpful to better understand economic decision making. This work aimed at finding the neural correlates of automatic, spontaneous emotional response to brands, showing how deeply integrated are consumption symbols within the cognitive and affective processes of individuals. Functional magnetic resonance imaging (fMRI) was measured during a visual oddball paradigm consisting in the presentation of scrambled pictures as frequent stimuli, colored squares as targets, and brands and emotional pictures (selected from the International Affective Picture System [IAPS]) as emotionally-salient distractors. Affective rating of brands was assessed individually after scanning by a validated questionnaire. Results showed that, similarly to IAPS pictures, brands activated a well-defined emotional network, including amygdala and dorsolateral prefrontal cortex, highly specific of affective valence. In conclusion, this work identified the neural correlates of brands within cognitive and affective processes of consumers.

Cross-sectional imaging of individual layers and buried interfaces of graphene-based heterostructures and superlattices

By stacking various two-dimensional (2D) atomic crystals on top of each other, it is possible to create multilayer heterostructures and devices with designed electronic properties. However, various adsorbates become trapped between layers during their assembly, and this not only affects the resulting quality but also prevents the formation of a true artificial layered crystal upheld by van der Waals interaction, creating instead a laminate glued together by contamination. Transmission electron microscopy (TEM) has shown that graphene and boron nitride monolayers, the two best characterized 2D crystals, are densely covered with hydrocarbons (even after thermal annealing in high vacuum) and exhibit only small clean patches suitable for atomic resolution imaging. This observation seems detrimental for any realistic prospect of creating van der Waals materials and heterostructures with atomically sharp interfaces. Here we employ cross sectional TEM to take a side view of several graphene-boron nitride heterostructures. We find that the trapped hydrocarbons segregate into isolated pockets, leaving the interfaces atomically clean. Moreover, we observe a clear correlation between interface roughness and the electronic quality of encapsulated graphene. This work proves the concept of heterostructures assembled with atomic layer precision and provides their first TEM images.

Treatment of acute exacerbations with non-invasive ventilation in chronic hypercapnic COPD patients with pulmonary hypertension

BACKGROUND AND OBJECTIVES

Chronic Obstructive Pulmonary Disease (COPD) is a slowly progressive airways disorder characterized by not fully reversible airflow obstruction, often presenting exacerbations of respiratory symptoms requiring hospitalization. Non-Invasive Ventilation (NIV) has been shown to be an effective adjunct to standard medical therapy in the treatment of acute respiratory failure. Secondary pulmonary hypertension leads to a rapid progression of the disease.

AIM

To evaluate the effect of NIV treatment in patients with acute exacerbation of COPD, with or without respiratory acidosis, and its effect in patients with pulmonary hypertension.

PATIENTS AND METHODS

We enrolled 61 consecutive subjects (M 41; F 20) with COPD admitted to our respiratory ward for acute respiratory exacerbation. Patients were divided into two groups on the basis of arterial pH (group A: 26 individuals with pH <7.35; group B: 35 with pH > or =7.35) and treated with optimal medical therapy (oxygen-therapy, systemic corticosteroids, bronchodilators, antibiotics) and NIV. Moreover, we evaluated functional autonomy thought Six Minute Walking Test (6 mWT), and pulmonary arterial pressure (by transthoracic echocardiography).

RESULTS

In group A NIV treatment was associated to a total regression of uncompensated respiratory acidosis (pH 7.36 vs. 7.29). In both groups we observed a significant reduction of PaCO2 (group A: 77.14 +/- 10.4 vs. 45.1 +/- 2.8 mmHg; group B: 70.1 vs. 44 +/- 3.9 mmHg) and an improvement in PaO2 (group A: 51.2 +/- 10.3 vs 84.2 mmHg; group B: 59 +/- vs. 87 +/- 3.3 mmHg). Total average duration of NIV administration was longer in Group A than in Group B (81.14 hours vs 55.83 hours). At the end of NIV treatment, we observed improvement in the autonomy of walking (175.1 meters vs 118.4 meters) in both groups. Patients with severe pulmonary hypertension (PASP > or =55 mmHg) showed a lower reduction of PaCO2 (47.8 vs. 43.7 mmHg) and a minor improvement of arterial pH (7.37 vs. 7.41) compared to patients with a lower value of pulmonary hypertension.

CONCLUSIONS

In this study we showed that NIV is useful in patients with or without uncompensated respiratory acidosis, through the improvement of symptoms, blood gases parameters, and walking autonomy. Patients with severe pulmonary hypertension are associated with poorer response to NIV treatment.

Sequence Diversity in tRNA Gene Locus A-L among Iranian Isolates of Entamoeba dispar

BACKGROUND

A number of methods for detecting diversity in Entamoeba have been described over the years. In the present study the genetic polymorphism of noncoding locus A-L was analyzed using PCR and sequencing in order to clarify the genotypic differences among E. dispar isolates.

METHODS

A total of 28 E. dispar from patients with gastrointestinal symptoms were determined and the genomic DNA was extracted directly from stool. For genotype analysis; Locus A-L was amplified by PCR and PCR products were sequenced. The sequences obtained were edited manually and aligned using Gene Runner software.

RESULTS

With sequencing of PCR products a reliable genetic diversity in size, number and position of the repeat units were observed among the Iranian E. dispar isolates in locus A-L gene. Sequences showed variation in length from 448bp to 507bp and seven distinct types were identified.

CONCLUSION

The genetic diversity of loci like A-L shows them to be suitable for epidemiological studies such as the characterization of the routes of transmission of these parasites in Iran.

Molecular epidemiology of cryptosporidiosis in Iranian children, tehran, iran

BACKGROUND

Cryptosporidium is a worldwide protozoan parasite and one of the most common causes of infection and diarrhea in humans and cattle. The aim of the present study was determination of subtypes of Cryptosporidium among children with diarrhea in Tehran by sequence analysis of the highly polymorphic 60-kDa glycoprotein (GP60) gene.

METHODS

Fecal samples were collected from 794 diarrheic children. Initial identification of Cryptosporidium was carried out on stool samples by Ziehl-Neelsen acid-fast staining method. DNA was extracted from positive microscopically samples and Cryptosporidium genotypes and subtypes were determined, accordingly.

RESULTS

Out of 794 collected samples, 19 (2.40%) were positive for Cryptosporidium oocysts. Sequences analysis of GP60 gene showed that 17 (89.47%) of the positive isolates were Cryptosporidium parvum and 2 (10.52%) were C. hominis. All subtypes of C. parvum isolates belonged to allele families IIa (6/17) and IId (11/17). The most common allele in all 17 isolates belonged to IId A20G1a (41.18%). A22G1 (IF) subtype was detected in two C. hominis isolates of the children.

CONCLUSION

The predominancy of C. parvum species (specially, IId A20G1a subtype) in current study underlines the importance of zoonotic Cryptosporidium transmission in Iran.

A comparative study of the responses of lithium borate and calcium sulphate phosphors in a TL personal dosemeter

This work summarises the results of a series of experiences made on Panasonic UD-802AS, a multi-element dosemeter that is currently used in Caorso Nuclear Power Plant for personnel external monitoring. Two main topics have been considered: energy response and the influence of working place dose rate on relative readings of the elements at the end of the monitoring period. The presence of four elements of different materials and filtrations gives the possibility of evaluating radiation energy by a simple algorithm, so that an accurate estimate of the personal dose equivalent can be provided; the good results of the participation of Caorso Individual Monitoring Service (IMS) to 'EURADOS 2008 intercomparison on whole-body dosemeters' account for the reliability of the method. A study on the response in low-dose rate fields is also reported, giving in practice interesting information about operational conditions.

Liquid injection atomic layer deposition of silver nanoparticles

Silver nanoparticles are being developed for applications in plasmonics, catalysts and analytical methods, amongst others. Herein, we demonstrate the growth of silver nanoparticles using an atomic layer deposition (ALD) process for the first time. The silver was deposited from pulses of the organometallic precursor (hfac)Ag(1,5-COD) ((hexafluoroacetylacetonato)silver(I)(1,5-cyclooctadiene)) dissolved in a 0.1 M toluene solution. Catalytic oxidative dehydrogenation of the silver was achieved using intermittent pulses of propanol. The effect of substrate temperature on the size and distribution of nanoparticles has been investigated over the temperature range 110-150 degrees C. Transmission electron microscopy reveals that the nanoparticles consist of face centred cubic, facetted silver crystallites. The localized surface plasmon modes of the nanoparticles have been investigated using electron energy loss spectroscopy mapping. The distributions of plasmons within the ALD nanoparticles are comparable to those grown by solution methods. Both dipolar and quadrupolar resonant modes are observed, which is consistent with previous discrete dipole approximation models. Energy loss mapping of a loss feature at 8.1 eV reveals that it correlates with the bulk or volume region of the silver nanoparticles investigated here.

Déficit homozygote en antithrombine de type HBS; à propos d'une famille

Congenital antithrombin (AT) deficiency is the most thrombotic genetic abnormality of haemostasis. Total quantitative deficits are lethal as early as life intra-uterine. Only homozygous mutations concerning the heparin-binding site are compatible with life. We report here the case of an 18 years old patient with recurrent deep venous thrombosis of the inferior members. Haemostasis exploration shows a decreased AT activity (11%) in the presence of heparin while AT progressive activity and AT antigen are normal. Two other homozygous sisters are identified in this family study. Molecular study of AT gene show Arg47-Cys substitution, already reported in the literature with patients of different geographic origins. Treatment of patients with homozygous AT type HBS deficiency is similar that for patients with heterozygous AT deficiency; a continuous prophylactic anticoagulant treatment is always necessary and AT concentrates infusions are required in all situations needing curative heparin treatment.

Analysis of urinary N-acetyl-S-(N-methylcarbamoyl)cysteine, the mercapturic acid derived from N,N-dimethylformamide

Human biotransformation of the industrial solvent N,N-dimethylformamide gives raise to N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) which has the longest half-life (about 23 h) among urinary metabolites of N,N-dimethylformamide. It could be used for monitoring industrial exposure over several workdays, by measuring it in urine samples collected at the end of the working week. This is consistent with the suggestions of the American Conference of Governmental Industrial Hygienists, which established a limit of 40 mg/l for the year 2000. An easy, cheap and user-friendly method has been developed for determination of urinary AMCC. Unlike currently available methods, it requires neither a time-consuming preparation phase nor gas chromatographic analysis with a nitrogen-phosphorus or mass detector. The method uses high-performance liquid chromatography (HPLC), with an UV detector at 436 nm. A 10-microl volume of urine is added to a carbonate-hydrogen carbonate buffer and mixed with a dabsyl chloride solution in acetonitrile. The reaction between AMCC and the reagent is performed at 70 degrees C for 10 min. The 'dabsylated' product is stable for at least 12 h. After brief centrifugation, the solution is ready for HPLC analysis using a C18 column (250 x 4.6 mm, 5 microm). The method is sensitive (detection limit 1.8 mg/l) and specific. It identified urinary AMCC in urine of 40 subjects not exposed to N,N-dimethylformamide with a median concentration of 3.9 mg/l. In urine samples from 20 workers exposed to N,N-dimethylformamide (5-40.8 mg/m3), AMCC concentrations ranged from 16 to 170 mg/l. Industrial toxicology laboratories with limited instrumentation will be able to use it in the biological monitoring of workers exposed to N,N-dimethylformamide.

The EGF and FGF receptors mediate neuroglian function to control growth cone decisions during sensory axon guidance in Drosophila

Cell adhesion molecules (CAMs) implement the process of axon guidance by promoting specific selection and attachment to substrates. We show that, in Drosophila, loss-of-function conditions of either the Neuroglian CAM, the FGF receptor coded by the gene heartless, or the EGF receptor coded by DER display a similar phenotype of abnormal substrate selection and axon guidance by peripheral sensory neurons. Moreover, neuroglian loss-of-function phenotype can be suppressed by the expression of gain-of-function conditions of heartless or DER. The results are consistent with a scenario where the activity of these receptor tyrosine kinases is controlled by Neuroglian at choice points where sensory axons select between alternative substrates for extension.