Beyond a Transmission Cable-New Technologies to Reveal the Richness in Axonal Electrophysiology

The axon is a neuronal structure capable of processing, encoding, and transmitting information. This assessment contrasts with a limiting, but deeply rooted, perspective where the axon functions solely as a transmission cable of somatodendritic activity, sending signals in the form of stereotypical action potentials. This perspective arose, at least partially, because of the technical difficulties in probing axons: their extreme length-to-diameter ratio and intricate growth paths preclude the study of their dynamics through traditional techniques. Recent findings are challenging this view and revealing a much larger repertoire of axonal computations. Axons display complex signaling processes and structure-function relationships, which can be modulated via diverse activity-dependent mechanisms. Additionally, axons can exhibit patterns of activity that are dramatically different from those of their corresponding soma. Not surprisingly, many of these recent discoveries have been driven by novel technology developments, which allow for in vitro axon electrophysiology with unprecedented spatiotemporal resolution and signal-to-noise ratio. In this review, we outline the state-of-the-art in vitro toolset for axonal electrophysiology and summarize the recent discoveries in axon function it has enabled. We also review the increasing repertoire of microtechnologies for controlling axon guidance which, in combination with the available cutting-edge electrophysiology and imaging approaches, have the potential for more controlled and high-throughput in vitro studies. We anticipate that a larger adoption of these new technologies by the neuroscience community will drive a new era of experimental opportunities in the study of axon physiology and consequently, neuronal function.

Lung cancer survival and sex-specific patterns in Portugal: A population-based analysis

INTRODUCTION

In Portugal, lung cancer (LC) is the first cause of cancer-related death and of death and disability combined. This study aims to analyze the overall survival (OS) and relative survival (RS) of patients diagnosed with LC in 2009-2011 by socio-demographic and tumor characteristics, and analyze sex-specific patterns.

METHODS

We estimated 5-year OS using the Kaplan-Meier method and 5-year net survival through the RS framework. Cox regression modeling was used to determine the hazard ratio (HR) of death associated with each independent variable.

FINDINGS

For the 11,523 cases analyzed, median 5-year OS was 264 days (95% confidence interval [CI]: 254.8-273.2), the cumulative OS was 13.6% and RS was 15.1%. Males had a lower median survival (237 days; 95% CI: 228.2-245.7) compared to females (416 days; 95% CI: 384.4-447.6) (p < 0.0001) and lower 5-year RS proportions (12.1% vs. 24.9%). RS progressively decreased with age (41.7% for age-group <40 to 7.2% for ≥80) and stage (66.6% for stage I to 2.4% for stage IV). As predictors of decreased survival, we identified male gender, increasing age >50, histologic types (squamous cell carcinoma, non-small cell lung cancer not otherwise specified, other unspecified and small cell lung cancer), and increasing stage. Compared to women, the risk of death in men was 37.7% higher (HR = 1.386; 95% CI: 1.295-1.484).

CONCLUSIONS

The differences between OS and RS were small, reflecting the high lethality of LC. Male gender and older age are factors related to poor prognosis. Histology also plays a role in survival prognosis and varies with gender, but the factor related to the worst survival is stage. Although the study reflects data from a decade ago, and major changes occurred in diagnosis, staging and treatment, particularly for advanced disease, as LC mortality is strongly correlated with late stage diagnosis, all efforts should be made to secure early diagnosis and improve survival prospects.

Impact of sociodemographic and economic determinants of health on COVID-19 infection: incidence variation between reference periods

OBJECTIVES

The COVID-19 pandemic hit Portugal in March 2020, causing widespread disruption to various aspects of society. While extensive research has been conducted on the significance of socio-economic disparities in infection risk, this study aims to enhance our understanding of their evolving relationship over time by analysing four distinct periods in 2020.

STUDY DESIGN AND METHODS

This retrospective observational ecological study included individuals residing in the Primary Healthcare Cluster areas of Almada-Seixal and Western Lisbon and Oeiras, who tested positive for SARS-CoV-2 through a polymerase chain reaction (PCR) test between the 2nd of March and the 8th of November of 2020. Using incidence rates for each specific neighbourhood (n = 29) and period, we explored the relationship between neighbourhood-level socio-economic variables and the risk of infection using negative-binomial regression models.

RESULTS

In the analysed period, a total of 8562 confirmed COVID-19 cases were identified. Overall incidence rates for each period were sequentially 2.74, 5.03, 3.99 and 14.29 COVID-19 cases per 100,000 person-days. Housing overcrowding, illiteracy rate and place of birth were associated with increased risk of infection, while age, congregate living, and employment in the secondary sector exhibited the opposite association. No association was consistent across all time periods.

CONCLUSIONS

Our findings support the idea that the influence of socio-economic determinants of health is not immutable throughout time. In a pandemic context where information, knowledge, beliefs, and behaviours are ever-changing and evolving, a dynamic, inclusive, and adaptable approach to disease control can lead to a more equitable distribution of improved outcomes, benefiting all strata of society.

National trends in the use of oral chemotherapy over 13 years

Background: Systemic cancer therapy has traditionally been administered using an intravenous (IV) route, implying patients’ frequent visits to hospitals to access to their therapy. If we consider the actual pipeline in oncology, oral chemotherapy will be the main component of cancer treatment in the next few years. This shift in the administration route requires different care models in order to guarantee treatment efficacy and safety.

Objective: To analyze time trends in oral chemotherapy consumption in Portugal.

Method: Oral chemotherapy consumption over a 13-year period (2008–2020) was analyzed, considering dispensed units by the administration route with respective costs, resorting to the drug regulatory agency (INFARMED I.P.) database. Oral consumption patterns were further explored using common daily doses (CDD) for three conditions, including chronic myeloid leukemia (CML), non-small-cell lung cancer (NSCLC), and breast cancer (BC), to adjust for the effect of varying doses. Data were analyzed descriptively resorting to Microsoft Office Excel 2010.

Results: Overall chemotherapy consumption increased +Δ54.7%, with the highest contribution in units observed in oral forms (+Δ58.8%). The total expenditure increased +Δ96.5%, and despite the increase in oral forms (+Δ221.6%), intravenous forms continued to be the major cost driver, with an important contribution from immunotherapy. Much of the increase was led by the approval of 40 new IV and 48 new oral cancer medications with higher costs introduced in the market. Using CDD as an alternative metric to units had varying impacts by indication. The observed increases seemed to focus on specific cancer sites with varying effect; in CML, there was a 2.39-fold increase, compared to 4.41 for NSCLC and 1.86 for BC. However, for BC, two distinct sub-patterns were observed for hormone therapy (increasing 1.83) and for the novel tyrosine kinase inhibitors (increasing 40.8).

Conclusion: The growing use of oral chemotherapy is obvious and calls for investments in supporting patients in managing medication adherence and adverse events. The shifts in the healthcare system are complex and need to be prioritized. Our data suggest that priority could be attributed to cancer sites driving innovation, namely, advanced breast cancer.

Bidirectional flow of action potentials in axons drives activity dynamics in neuronal cultures

Objective. Recent technological advances are revealing the complex physiology of the axon and challenging long-standing assumptions. Namely, while most action potential (AP) initiation occurs at the axon initial segment in central nervous system neurons, initiation in distal parts of the axon has been reported to occur in both physiological and pathological conditions. The functional role of these ectopic APs, if exists, is still not clear, nor its impact on network activity dynamics.Approach. Using an electrophysiology platform specifically designed for assessing axonal conduction we show here for the first time regular and effective bidirectional axonal conduction in hippocampal and dorsal root ganglia cultures. We investigate and characterize this bidirectional propagation both in physiological conditions and after distal axotomy.Main results.A significant fraction of APs are not coming from the canonical synapse-dendrite-soma signal flow, but instead from signals originating at the distal axon. Importantly, antidromic APs may carry information and can have a functional impact on the neuron, as they consistently depolarize the soma. Thus, plasticity or gene transduction mechanisms triggered by soma depolarization can also be affected by these antidromic APs. Conduction velocity is asymmetrical, with antidromic conduction being slower than orthodromic.Significance.Altogether these findings have important implications for the study of neuronal functionin vitro, reshaping our understanding on how information flows in neuronal cultures.

Standardising clinical outcomes measures for adult clinical trials in Fabry disease: A global Delphi consensus

BACKGROUND

Recent years have witnessed a considerable increase in clinical trials of new investigational agents for Fabry disease (FD). Several trials investigating different agents are currently in progress; however, lack of standardisation results in challenges to interpretation and comparison. To facilitate the standardisation of investigational programs, we have developed a common framework for future clinical trials in FD.

METHODS AND FINDINGS

A broad consensus regarding clinical outcomes and ways to measure them was obtained via the Delphi methodology. 35 FD clinical experts from 4 continents, representing 3389 FD patients, participated in 3 rounds of Delphi procedure. The aim was to reach a consensus regarding clinical trial design, best treatment comparator, clinical outcomes, measurement of those clinical outcomes and inclusion and exclusion criteria. Consensus results of this initiative included: the selection of the adaptative clinical trial as the ideal study design and agalsidase beta as ideal comparator treatment due to its longstanding use in FD. Renal and cardiac outcomes, such as glomerular filtration rate, proteinuria and left ventricular mass index, were prioritised, whereas neurological outcomes including cerebrovascular and white matter lesions were dismissed as a primary or secondary outcome measure. Besides, there was a consensus regarding the importance of patient-related outcomes such as general quality of life, pain, and gastrointestinal symptoms. Also, unity about lysoGb3 and Gb3 tissue deposits as useful surrogate markers of the disease was obtained. The group recognised that cardiac T1 mapping still has potential but requires further development before its widespread introduction in clinical trials. Finally, patients with end-stage renal disease or renal transplant should be excluded unless a particular group for them is created inside the clinical trial.

CONCLUSION

This consensus will help to shape the future of clinical trials in FD. We note that the FDA has, coincidentally, recently published draft guidelines on clinical trials in FD and welcome this contribution.

Quality of Life and Characterization of Patients With Atopic Dermatitis in Portugal: The QUADEP Study

Objectives: To investigate the quality of life (QOL) of and to characterize patients with atopic dermatitis (AD) in Portugal. Methods: This was a cross-sectional study of patients with AD and other eczemas. Skindex-29, Skindex-teen, and the Childhood Atopic Dermatitis Impact Scale (CADIS) were the instruments used to assess QOL in adults, teenagers, and children, respectively. The SF-12 was also used, and disease severity was evaluated using the Patient-Oriented SCORAD (PO-SCORAD) instrument. Associations with QOL were assessed based on the odds ratio (OR). P values <.05 and 95%CIs were considered statistically significant. Results: The study population comprised 162 participants aged 0.5-74 years. We found that 37.3% of AD patients consider their disease disabling and that more than half of the patients feel stigmatized by society. The mean Skindex score for AD was 39.68, and the impact on QOL was severe in 44%. “Symptoms” was the most affected category in adults. AD was moderate to severe in 87% of the sample. One of the factors that most influenced poorer QOL in AD was age: with increasing age, the Skindex is likely to increase (OR, 1.03; 95%CI, 1.00-1.06). “Considering the disease a disability” was also associated (OR, 6.72; 95%CI, 2.56-17.63). QOL worsens with increasingly affected body area (OR, 1.07; 95%CI, 1.03-1.11) and the presence of edema (OR, 2.0; 95%CI, 1.23-3.40). Conclusions: This is the first study to provide data on QOL in patients with AD in Portugal. Our data show an expected negative impact. More awareness-raising activities are needed to increase knowledge, decrease stigmatization, and, consequently, address the factors involved in the QOL of patients with AD.

Factors related to tuberculosis delays: Evidence from nationwide retrospective study in Portugal

Background

Globally, tuberculosis (TB) remains one of the top 10 causes of deaths and the leading cause from a single infectious agent. Delayed TB diagnosis and/or treatment may result in the transmission of bacilli, increasing infectivity, the risk of severe disease states, morbidity and mortality. It is essential to identify the factors that prolong delays in TB services so that health planners can initiate necessary measures to control TB infections.

Methods

A nationwide retrospective study was conducted from 2010 until 2013 to analyze tuberculosis delays under the setting of the Portuguese National Tuberculosis Control Programme. There were 16824 participants who were from 25 administrative districts under 7 regions and were originated from 70 countries in the world. The log-rank test, Cox's regression, and the Kaplan-Meier method have employed to analyze TB delay data.

Results

The median of patients` delay was 34 days with interquartile ranges (IQR) 50 days. Alcohol addicted people with TB infection were delayed by 40 days with 95% CI 37.73-42.28 whereas the non-addicted people took 33 days with 95% CI 32.35-33.65. The median diagnostic delay was 12 days with an IQR of 38 days. The female participants were delayed more than that of male (median delay for female 17 days with 95% CI 15.80-18.19) in TB diagnosis. Further, comorbidities e.g. lung cancer affected TB candidates were delayed more than their counterparts (median delay 37 days with 95% CI 23.29-50.70). The median of public health delays was 63 days with IQR 72 days. The females were delayed more than that of males (median delay 68 days with 95% CI 66.06-69.94). The adjusted Cox's regression identifies the features - older age, female, drug addiction, and community residence as potential factors that might affect TB delays.

Conclusions

It is essential to emphasize on the influencing dynamics - older age, female patients, HIV patients, alcohol addiction, and comorbidities to minimize TB delays.

Key messages

To minimize spreading risk of TB infections the dynamics of TB delays e.g. older age, female patients, drug, and alcohol addiction, comorbidities should be prioritized in the TB control programs. Special attention should be given to other lung diseases while diagnosing TB infections.

Factors that influence the response time in STEMI patients in Lisbon 2017

The success of the ST-segment elevation myocardial infarction (STEMI) approach is based on early diagnosis and on the institution of timely reperfusion therapy, with response times remaining variable. The objective of this study was to determine which factors influenced the response time to patients with STEMI until the treatment with coronary reperfusion from the prehospital service or the emergency room in three hospitals in the greater Lisbon area in 2017. An epidemiological, cross-sectional, retrospective, descriptive study with an analytical component was performed, with data from the National Institute of Medical Emergency (INEM) and clinical trials of patients. Patients who were not referred to these hospitals were excluded. Univariate statistical analysis was performed, as well as c2 tests, t-student and logistic regression model (r &lt; 0.05). The population included 95 patients, the majority being male (67.4%), and with a mean age of 63.8 years. 61.1% were hypertensive and the majority (87.4%) had no signs of previous heart failure. The mean door-to-balloon time was 159 minutes, with 57.4% showing time greater than 120 minutes. In patients in whom the INEM Coronary Greenway was activated, mean door-to-balloon time was 99 minutes. Diagnostic, symptom-admission and transport times showed a statistically significant association with the door-to-balloon time in the bivariate analysis. The times are fulfilled in the prehospital service, but in the hospital, services can be improved through the early accomplishment of electrocardiogram and the optimization of interhospital transport.

Key messages

Reducing ECG time and inter-hospital transport time improves STEMI response and outcome. Time is muscle is the main message for de concern of identifying influence factors of STEMI response time.

Relevance of quantification in brain PET studies with 18F-FDG

The inclusion of ¹⁸F-FDG PET as a biomarker in the diagnostic criteria of neurodegenerative diseases and its indication in the presurgical assessment for drug-resistant epilepsies allow to improve specificity of these diagnosis. The traditional interpretation of neurological PET studies has been performed qualitatively, although in the last decade, several quantitative evaluation methods have emerged. This technical development has become relevant in clinical practice, improving specificity, reproducibility and reducing the interrater reliability derived from visual analysis. In this article we update/review the main imaging processing techniques currently used. This may allow the Nuclear Medicine physician to know their advantages and disadvantages when including these procedures in daily clinical practice.

Eczema and Urticaria in the Adult Population in Portugal: A Prevalence Study

BACKGROUND AND AIMS

Eczema and urticaria are both inflammatory skin diseases. The prevalence of both diseases varies worldwide and the reasons are unknown. We aimed to investigate the eczema and urticaria prevalence in the Portuguese adult (≥16 years-old) population.

MATERIALS AND METHODS

A telephone interview survey was performed in the last quarter of 2017. To calculate the prevalences, subjects should have been previously diagnosed with eczema/urticaria by a health professional, be aged ≥16 years-old, and reside in Portugal. The sample had a proportion that was approximately representative by population, region, gender, and age group. Odds ratios were performed to measure associations with prevalences. SPSS statistics and values of p<0.05 with 95% confidence intervals were considered statistically significant.

RESULTS

5,000 phone calls were analysed. The prevalence of eczema and urticaria in Portugal is 4.4% and 3.4%, respectively. Algarve is the region with the highest prevalence for both diseases. Being a female is the factor that most influenced these diseases with an OR=1.99 (p<0.001; CI 1.49-2.66) for eczema and 1.73 (p=0.001; CI 1.25 - 2.40) for urticaria, with also higher prevalences (5.7% and 4.2%, respectively).

CONCLUSIONS

The prevalences found are higher than in previous studies in Portugal and comparable to results from other countries. Comparisons among prevalence of eczema are affected by several obstacles. Regarding urticaria, our results seem to be in the same line as others. Being female with eczema and urticaria is more common and represents a higher risk factor than male subjects. According to Harrop et al., 2007, in Europe, atopic eczema is 0.14-0.60% of general eczema. In this way, we can estimate that prevalence of atopic eczema in Portugal is around 0.61-2.64%.

Recombination in liquid-filled ionization chambers beyond the Boag limit

PURPOSE

The high mass density and low mobilities of charge carriers can cause important recombination in liquid-filled ionization chambers (LICs). Saturation correction methods have been proposed for LICs. Correction methods for pulsed irradiation are based on Boag equation. However, Boag equation assumes that the charge ionized by one pulse is fully collected before the arrival of the next pulse. This condition does not hold in many clinical beams where the pulse repetition period may be shorter than the charge collection time, causing overlapping between charge carriers ionized by different pulses, and Boag equation is not applicable there. In this work, the authors present an experimental and numerical characterization of collection efficiencies in LICs beyond the Boag limit, with overlapping between charge carriers ionized by different pulses.

METHODS

The authors have studied recombination in a LIC array for different dose-per-pulse, pulse repetition frequency, and polarization voltage values. Measurements were performed in a Truebeam Linac using FF and FFF modalities. Dose-per-pulse and pulse repetition frequency have been obtained by monitoring the target current with an oscilloscope. Experimental collection efficiencies have been obtained by using a combination of the two-dose-rate method and ratios to the readout of a reference chamber (CC13, IBA). The authors have also used numerical simulation to complement the experimental data.

RESULTS

The authors have found that overlap significantly increases recombination in LICs, as expected. However, the functional dependence of collection efficiencies on the dose-per-pulse does not change (a linear dependence has been observed in the near-saturation region for different degrees of overlapping, the same dependence observed in the nonoverlapping scenario). On the other hand, the dependence of collection efficiencies on the polarization voltage changes in the overlapping scenario and does not follow that of Boag equation, the reason being that changing the polarization voltage also affects the charge collection time, thus changing the amount of overlapping.

CONCLUSIONS

These results have important consequences for saturation correction methods for LICs. On one hand, the two-dose-rate method, which relies on the functional dependence of the collection efficiencies on dose-per-pulse, can also be used in the overlapping situation, provided that the two measurements needed to feed the method are performed at the same pulse repetition frequency (monitor unit rate). This result opens the door to computing collection efficiencies in LICs in many clinical setups where charge overlap in the LIC exists. On the other hand, correction methods based on the voltage-dependence of Boag equation like the three-voltage method or the modified two-voltage method will not work in the overlapping scenario due to the different functional dependence of collection efficiencies on the polarization voltage.

The blood-tendon barrier: identification and characterisation of a novel tissue barrier in tendon blood vessels

In the last decade, nanobiotechnology research has emerged as a revolutionising new approach to the 21st century pharmaceutical challenges, offering valuable gains in a vast set of biomedical applications. In the field of bone tissue engineering, a broad range of nanotechnology-based delivery systems have been researched and the most recent developments in high-throughput technology and in silico approaches are creating very high expectations. This review presents a comprehensive overview of the emergent nanotechnology-based materials, processing techniques and research strategies for the delivery of pharmaceutics to bone including the materials general characteristics and the available drug delivery systems to distribute agents systemically or locally. Complementary to what was stated above, it also reviews the latest high-throughput processing techniques and the existent in silico tools (mathematical and computational models) used to help on the design of delivery systems.

Assessing Medication Beliefs of Mental Health Professionals: The Portuguese Version of the Medication Alliance Beliefs Questionnaire

Introduction

Clinician's attitudes are an important consideration in implementing adherence strategies and that these attitudes can be successfully improved as a result of training. The 22-item Medication Alliance Beliefs Questionnaire (MABQ; Byrne et al.2008) was used to assess clinician attitudes towards non-adherence. The MABQ contains five subscales reflecting the clinician's self-efficacy (adequacy), the satisfaction (work satisfaction); their appraisal of their self-worth (self-esteem), their outcome expectancies (pessimism) in relation to non-adherent patients, and the extent to which they understand the difficulties patients might experience in trying to adhere to treatment (empathy).

Aims/objectives

To develop the Portuguese version of the MABQ.

Methods

The MABQ was translated and adapted for Portuguese language. The translation was done by the first author (AC). The accuracy of this translation was discussed in a two focus group of experts, providing opinion on face and content validity. After pre-testing, the final version of the Portuguese translation was produced.

Results

A convenience sample of 65 mental health professionals working in a variety of settings is being collected. The average score in MABQ was 80.06 (SD 9.5). The value of internal reliability coefficient α was 0.80. The intraclass correlation coefficient of total MABQ score was 0.35. The t-test showed that there were no statistically significant differences between the mean values of the measurement scale at two different times (80.4 vs.76.2; P = 0.02).

Conclusion

The attitudes of mental health professionals may have a predictive relationship with treatment outcomes of patients with mental health disorders. The validation of the Portuguese version of MABQ will provide professionals with a new tool to evaluate crucial issues related to medication beliefs.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

How we can enhance treatment adherence? Perspective of patients and clinicians

Introduction

Non-adherence to antipsychotic medication is commonly found in mental health disorders (MHD), thus forming a major obstacle to long-term maintenance treatment and contributing to high relapse rates and also can influence the attitudes and beliefs of mental health professionals (MHP).

Objectives

–assess the beliefs of MHP;

–assess perception of illness in patients with MHD.

Aims

Contribute to treatment adherence of patients with MHD, through developing adequate strategies to their needs.

Methods

In this cross-sectional study, we use a convenience sample of patients with MHD attending in the mental health departments of three general hospitals in Lisbon great area. Data is being collected through individual interviews. We have applied clinical and socio-demographic questionnaire and additional measures to assess symptom severity, treatment adherence and attitudes towards medication. For MHP, we used a optimism scale (ETOS), Difficulty Implementing Adherence Strategies (DIAS); Medication Alliance Beliefs Questionnaire (MABQ).

Results

Two convenience samples were composed by 150 patients with MHD (mean age: 39.7; SD ± 9.8) and 65 MHP (mean age: 37.0; sd 8.3) working in a variety of settings is being collected. From the perspective of patients, the most important reason for adherence is to accept the illness (54,7%, n = 82). 50.8% (n = 33) of MHP believes that if patients are unmotivated for treatment, adherence strategies are unlikely to be effective. 43.1 (n = 28) of MHP agrees that if patients do not accept their illness, any adherence strategies that result.

Conclusion

With this study, we expect to gain further knowledge on the factors related patients and MHP that might influence compliance and, therefore, contribute to the development of effective strategies to promote treatment adherence in MHD.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Assessing Strategies to Improve Antipsychotic Adherence: The Portuguese Version of the Difficulty Implementing Adherence Strategies

Introduction

Non-adherence is a problem throughout medicine and there are many strategies that are used to improve antipsychotic adherence. A review of the literature identified 33 commonly cited strategies for enhancing consumer adherence. Three core themes were identified: Information/Education; Behavioural strategies; and Cognitive/Motivational strategies.

Aims/objectives

To develop the Portuguese version of the DIAS.

Methods

The DIAS was translated and adapted for Portuguese language. The translation was done by the first author (AC). The accuracy of this translation was discussed in a two focus group of experts, providing opinion on face and content validity. The participants were asked to rate how often they had difficulties using each of the 33 strategies with consumers who were non-adherent. A four point Likert scale was used (1 = never; 4 = always) such that higher scores indicated more frequent difficulty using the strategy.

Results

A convenience sample of 65 mental health professionals working in a variety of settings is being collected. The average score in DIAS was 85.0 (SD14.6). The value of internal reliability coefficient α was 0.93. The intraclass correlation coefficient of total MABQ score was 0.45. The t-test showed that there were no statistically significant differences between the mean values of the measurement scale at two different times (84.5 vs.90.5; P = 0.04).

Conclusion

Interventions to improve antipsychotic adherence would benefit from further research. However, it is important always to bear in mind that none of these strategies can be a substitute a positive therapeutic alliance. The Portuguese version of DIAS will provide professionals with a new tool to evaluate the frequency how strategies are implemented and the impact of each strategy in treatment adherence.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Association between suicide attempts and insight among patients with bipolar disorders

Introduction

Insight is an important factor associated with non-compliance and poor outcome. Poor level of insight has been described as a characteristic in patients with acute bipolar disorder with more unawareness in social consequences. In contrast, awareness of having a mental disorder, of its symptoms, of its consequences, and/or of the need for treatment is associated with a number of positive prognostic indicators. Insight is also linked, however, to depression and suicidal ideation in bipolar disorder.

Objectives

(1) Assess the illness perception. (2) Assess the impact of insight in suicidal tendencies.

Aims

Contribute to development measures to improve the insight in bipolar disorders.

Methods

In this cross sectional study we use a convenience sample of patients with bipolar disorder attending in the mental health departments of three general hospitals in Lisbon great area. We have applied clinical and socio-demographic questionnaire and additional measures to assess symptom severity, treatment adherence and illness perception.

Results

A samples was composed by 64 patients with bipolar disorder (mean age = 38.7; SD ± 10.1). A total of 48.4% patients (n = 31) had made a suicide attempted and 23.4% (n = 15) of this patient done 5 or more attempted suicide. We found a significant correlation with symptoms and insight (rs = 0.56; P < 0.01).

Conclusion

Mental health professionals often utilize insight as an indicator of prognosis, because of its association with treatment adherence. The findings of the current study suggest that having intact or good insight may be an indicator for suicidal ideation among patients with bipolar disorders. A brief psychoeducational approach could potentially be effective. We recommend a combined approach to Improve clinical insight in bipolar disorder.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Validation of semi-quantitative methods for DAT SPECT: influence of anatomical variability and partial volume effect

The aim of this work was to evaluate the influence of anatomical variability between subjects and of the partial volume effect (PVE) on the standardized Specific Uptake Ratio (SUR) in [(123)I]FP-bib SPECT studies. To this end, magnetic resonance (MR) images of 23 subjects with differences in the striatal volume of up to 44% were segmented and used to generate a database of 138 Monte Carlo simulated SPECT studies. Data included normal uptakes and pathological cases. Studies were reconstructed by filtered back projection (FBP) and the ordered-subset expectation-maximization algorithm. Quantification was carried out by applying a reference method based on regions of interest (ROIs) derived from the MR images and ROIs derived from the Automated Anatomical Labelling map. Our results showed that, regardless of anatomical variability, the relationship between calculated and true SUR values for caudate and putamen could be described by a multiple linear model which took into account the spill-over phenomenon caused by PVE (R² ≥ 0.963 for caudate and ≥0.980 for putamen) and also by a simple linear model (R(2) ≥ 0.952 for caudate and ≥0.973 for putamen). Calculated values were standardized by inverting both linear systems. Differences between standardized and true values showed that, although the multiple linear model was the best approach in terms of variability (X² ≥ 11.79 for caudate and ≤7.36 for putamen), standardization based on a simple linear model was also suitable (X² ≥ 12.44 for caudate and ≤12.57 for putamen).

Monte Carlo simulations versus experimental measurements in a small animal PET system. A comparison in the NEMA NU 4-2008 framework

In this work a comparison between experimental and simulated data using GATE and PeneloPET Monte Carlo simulation packages is presented. All simulated setups, as well as the experimental measurements, followed exactly the guidelines of the NEMA NU 4-2008 standards using the microPET R4 scanner. The comparison was focused on spatial resolution, sensitivity, scatter fraction and counting rates performance. Both GATE and PeneloPET showed reasonable agreement for the spatial resolution when compared to experimental measurements, although they lead to slight underestimations for the points close to the edge. High accuracy was obtained between experiments and simulations of the system's sensitivity and scatter fraction for an energy window of 350-650 keV, as well as for the counting rate simulations. The latter was the most complicated test to perform since each code demands different specifications for the characterization of the system's dead time. Although simulated and experimental results were in excellent agreement for both simulation codes, PeneloPET demanded more information about the behavior of the real data acquisition system. To our knowledge, this constitutes the first validation of these Monte Carlo codes for the full NEMA NU 4-2008 standards for small animal PET imaging systems.

Simulated FDG-PET studies for the assessment of SUV quantification methods

AIM

To study in detail the accuracy and repeatability of three commonly used methods for SUV estimation in solitary pulmonary nodules.

MATERIAL AND METHODS

We have designed a realistic framework based on simulated FDG-PET acquisitions from an anthropomorphic activity model that included solitary pulmonary nodules (different sizes) of well-known SUV. This framework enables us to compare the SUV values obtained from the reconstructed PET images with the real SUV values. Three commonly used methods (SUVmax, SUVmean and SUV50) were used to estimate the tumor activity.

RESULTS

Our results showed the tumor activity was overestimated using SUVmax and clearly subestimated using SUVmean. Instead, the quantification of SUV50 showed great agreement with the simulated tumor activity and only slight subestimation was found for very small lesions. On the other hand, SUVmean showed better performance than SUV50 in terms of repeatability, providing variabilities below 5% for all tumor sizes and for injected doses as low as 111 MBq.

CONCLUSIONS

Our findings showed that SUV50 provided better performance for estimating accurately tumor SUV values in pulmonary nodules, but SUVmean showed better results in terms of repeatability.