Acclimatization and Foraging of Native Brazilian Stingless Bees in Arenas with Covering Materials of Different Spectral Properties

The use of Meliponini for crop pollination in protected environments is practically non-existent. One of the reasons is the difficulty of acclimatizing Meliponini to the temperature and light conditions inside greenhouses. We investigated how covering materials used in greenhouses, which filter different intensities of ultraviolet (UV) light, affect the foraging behaviors, flight orientation, attraction to walls and ceilings, and mortality of Scaptotrigona cf. postica (Letreille), Frieseomelitta varia (Lepeletier), and Melipona quadrifasciata (Lepeletier). The experiments were conducted in 5.3 m3 arenas covered with four types of plastic films that do not polarize sunlight, with UV transmittance levels ranging from 0.1 to 54%, compared to a transparent glass control. The temperature inside the arenas varied between treatments, from 27 ± 3°C to 31 ± 2°C. All three species collected resources and returned to the colony, regardless of the covering material. However, the proportion of this behavior, the number of bees attracted to the ceiling and wall, and mortality varied among treatments and/or throughout the confinement days for each species. Melipona quadrifasciata and F. varia acclimatized better to the confined environments than S. cf. postica and showed consistent resource collection behavior throughout the confinement days in all tested materials, except for the one that filtered around 90% of UV. In all three species, the mortality gradually decreased throughout the confinement days. The results indicate that the choice of covering material, considering its optical characteristics, can be crucial to ensure greater effectiveness of the pollination services provided by stingless bees in protected systems.

Body size and the architecture of the visual system in crepuscular and diurnal bees

Crepuscular bees have larger compound eyes, ommatidia and ocelli than diurnal bees. These visual adaptations allow these bees to forage during twilight. While the sizes of visual organs are positively correlated with body size in diurnal bees, this relationship is as yet unclear in crepuscular bees. Here we measured the sizes of the ocellus; compound eyes; ommatidial density; and dorsal, frontal and ventral facets of 11 phylogenetically related bee species with different temporal patterns. We tested whether and how each of these visual attributes is correlated with body size and/or temporal pattern. Except for ommatidial density and size of the frontal ommatidia, which are similar in crepuscular bees of different sizes, we found that all other visual variables in diurnal and crepuscular bees are correlated with both body size and temporal pattern. The lower variability in ommatidial density among crepuscular bees suggests that their eyes operate on the threshold between light sensitivity and visual acuity. Furthermore, similar frontal ommatidial sizes in bees of different sizes indicate that this eye region is under higher evolutionary pressure in small than in large crepuscular bees to ensure light sensitivity. Finally, those crepuscular bees from different families convergently share the same visual characteristics.

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

Contrast-induced nephropathy following PCI: can we calculate a safe contrast volume?

Introduction

Acute kidney injury (AKI) due to contrast induced nephropathy (CIN) is a common complication after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS), and is associated with prolonged hospitalizations and elevated cardio and renovascular morbidity. Scientific evidence demonstrates that the mean volume of contrast (VolC) and ratio with creatinine clearance (CrCl) (VolC/CrCl) are independent predictors of CIN, but the accepted optimal value remains controversial.

Objective

Population characterization. To evaluate whether the calculation of VolC using the VolC/ClCr ratio <3.7 used in our Cath lab during PCI of ACS allows preventing the development of AKI by CIN, and whether the development of early vs late AKI influences outcomes.

Methods

Retrospective study between 2017/2020, composed of n=378 patients who suffered ACS. Descriptve analysis was carried out regarding the demographic and clinical characteristics of the patients. Chi-Square test was used for categorical variables and the T-Student test for numerical variables, with a significance level of 95%.

Results

A total of 378 patients were identified, with a mean age of 64.5±11.2 years, 78.6% were male. 60.1% had hypertension, 48.4% dyslipidemia, 24.3% diabetes, 2.6% chronic renal failure (CRF) and 1.6% heart failure. Of these, 12.7% developed AKI (<24h in 1.9% vs ≥24h in 10,8%). Indepedent prognostic factors for development of AKI were smokers (AKI ≥24h 7 (4.8%) vs AKI<24h 2 (1.4%), p=0.001), diabetes (AKI≥24h 17 (19%) vs AKI <24h 2 (2.2%), p=0.007), CRF (AKI ≥24h 6 (60%) vs AKI <24h 1 (10%), p=0.001), CrCl (AKI ≥24h 65.8±27.1, p=0.001), ratio VolC/CrCl (AKI ≥24h 3.3±2.5, p=0.001) and LVEF (AKI ≥24h 51.4±9.7, p=0.001). Mortality afected 4.2% of the patients, and was more frequente in AKI subjects (AKI ≥24h 7 (70%) vs AKI <24h 1 (10%), p=0.001). Using a ratio <3.7 allowed to prevent AK <24h but not AKI ≥24h (AKI <24h ratio <3.7 = 3 (1%) vs ratio ≥3.7 = 9 (4.1%), p=0.001) (AKI ≥24 ratio <3.7 = 30 (25%) vs ratio ≥3.7 = 11 (9.7%), p=0.001). A ratio <2.0 allowed to prevent both early and late AKI (AKI <24h ratio <2.0 = 0 (0%) vs ratio ≥2.0 = 7 (4.5%), p=0.001) (AKI ≥24 ratio <2.0 = 11 (5.6%) vs ratio ≥2.0 = 30 (19.1%), p=0.001).

Conclusion

In patients submitted to ACS PCI, the development of AKI increases mortality, especial if AKI emerge after 24h. We report a more suitable ratio VolC/ClCr <2.0, that allow us to calculate a safe VolC that will help to prevent both early and late AKI in selected patients wtih ACS.

Funding Acknowledgement

Type of funding sources: None.

A three-dimensional atlas of the honeybee central complex, associated neuropils and peptidergic layers of the central body

The central complex (CX) in the brain of insects is a highly conserved group of midline-spanning neuropils consisting of the upper and lower division of the central body, the protocerebral bridge, and the paired noduli. These neuropils are the substrate for a number of behaviors, most prominently goal-oriented locomotion. Honeybees have been a model organism for sky-compass orientation for more than 70 years, but there is still very limited knowledge about the structure and function of their CX. To advance and facilitate research on this brain area, we created a high-resolution three-dimensional atlas of the honeybee's CX and associated neuropils, including the posterior optic tubercles, the bulbs, and the anterior optic tubercles. To this end, we developed a modified version of the iterative shape averaging technique, which allowed us to achieve high volumetric accuracy of the neuropil models. For a finer definition of spatial locations within the central body, we defined layers based on immunostaining against the neuropeptides locustatachykinin, FMRFamide, gastrin/cholecystokinin, and allatostatin and included them into the atlas by elastic registration. Our honeybee CX atlas provides a platform for future neuroanatomical work.

The advantages of being crepuscular for bees: major pollen gain under low competition during the brief twilight period

The shift in flight activity from daylight to twilight in crepuscular bees is assumed to have evolved to escape competitors, but quantitative confirmation of this hypothesis has never been demonstrated clearly. Pseudobombax longiflorum is a chiropterophilous plant, with flowers presenting large amounts of pollen throughout anthesis, thus attracting not only nocturnal visitors, but also crepuscular and diurnal bees. In this dynamic system, the fraction of pollen that flows to different visitors and the putative role of bees in pollination remain unknown. We analysed floral biology, the frequency of visitors in periods with different light intensities and the rate of pollen removal by each visitor group. A pollinator-exclusion experiment showed that bees were not pollinators of Pseudobombax longiflorum, although they collected > 60% of the pollen from their flowers. Crepuscular bees gained the greatest amount of pollen in the few minutes when they foraged without either nocturnal or diurnal competitors, confirming the advantage of foraging under low light. During the short twilight period, these bees foraged alone and removed 26.5 and 15 times more pollen per minute than nocturnal and diurnal visitors, respectively. Therefore, pollen removal by crepuscular bees is particularly efficient when they forage in the brief period while competitors are absent.

Premature acute coronary syndrome

Introduction

The prevalence of acute coronary syndrome (ACS) at an early age is rising, resulting in higher morbidity and mortality rates.

Purpose

To characterize patients admitted with premature ACS, comparing with those with non-premature ACS.

Methods

A retrospective study encompassing patients of a National Registry of ACS was performed. We compared two groups: one composed of men <55 and women <65 years-old; and other with men ≥55 and women ≥65 years-old at the ACS admission. Clinical characteristics, in-hospital evolution and 1-year clinical outcomes were analysed. Primary endpoint was the composite of in-hospital mortality, stroke and re-myocardial infarction (MI). Secondary endpoints were re-MI, stroke, in-hospital and 1-year mortality, 1-year cardiovascular (CV) and non-CV readmissions.

Results

A total of 26523 patients were enrolled and 6637 (25%) had premature ACS, with a mean age of 49±7 years-old. It was found a larger prevalence of smoking habits, obesity and dyslipidemia, but not diabetes. ST-segment elevation MI (STEMI) was the main admission diagnosis (51,2% vs 40,3%), with more frequent activations of the STEMI network (17,1% vs 12,8%) and a consequently shorter time from symptom onset to admission (483 vs 584 min). Coronary angiogram was largely performed in younger patients (91,4% vs 82,1%), mainly revealing one-vessel disease (49,3% vs 34,3%). They had lower Killip-Kimbal (KK) class (6% vs 18,1% with KK class >1) and mostly preserved left ventricular ejection fraction (LVEF) (67,3% vs 58,6%). Major bleeding (0,9% vs 1,7%), sustained ventricular tachycardia (1,1% vs 1,5%) and mechanical complications (0,2% vs 0,7%) were uncommon. Composite endpoint was more frequent in non-premature ACS patients (6,2% vs 1,9%). Non-premature age, KK class >1, multivessel disease and depressed LVEF were independent predictors of primary endpoint (each with p<0,001). Younger patients had inferior rates of in-hospital mortality (1% vs 4,7%), re-MI (0,5% vs 1%) and stroke (0,4% vs 0,7%). One-year mortality (1,7% vs 9,1%), and 1-year CV (9,7% vs 15,5%) and non-CV readmissions (3,7% vs 8,2%) were also lower. All comparative data presented have a statistically significant p-value (p<0,012).

Conclusions

Premature ACS affects 25% of the ACS population, mostly presenting with STEMI, but generally associated with better clinical evolution. Nevertheless, primary prevention is essential to correct modifiable CV risk factors and reduce coronary events in these patients.

Funding Acknowledgement

Type of funding source: None

P871 Giant left ventricular (pseudo?)aneurysm complicating anterior myocardial infarction

Introduction

Clinical approach of cardiac aneurysms and pseudoaneurysms is significantly distinct. Therefore, it is crucial to accurately differentiate these two entities, which could be a real challenge.

Case report

We describe a case of a 55-year-old woman, with hypertension and previous smoking habits. She was admitted in our Cardiology Department with the diagnosis of anterior acute myocardial infarction, and was submitted to emergent coronariography, unveiling an occlusion of the middle segment of the anterior descending artery. She underwent successful primary percutaneous coronary intervention (PCI) 1h45 after the chest pain onset. Transthoracic echocardiogram (TTE) revealed depressed left ventricle ejection fraction (LVEF 30%), with akinesia of anterior and septal walls and all apical segments. She evolved in Killip-Kimbal class 2 and was discharged clinically stable. One week later, the patient performed a control TTE that showed an apical thrombus, with a small pericardial effusion, and she initiated warfarin. Three weeks later, a reevaluation TTE demonstrated a severe increase of the left ventricle dimensions, with LVEF 32%, and a small pericardial effusion. In apical 4-chambers incidence, it was visualized a linear structure (42 mm x 5 mm) attached to the endocardial border of the anterolateral apical segment and to the apical segment of the interventricular septum, of undefined nature. The apical segments were dyskinetic and had a very thin wall, which could correspond to aneurysm versus pseudoaneurysm. To clarify these findings, the patient performed a cardiac magnetic resonance revealing a large anterior myocardial infarction complicated with extensive myocardial necrosis, severe depression of LV systolic function (LVEF 25%) and septum rupture distal to the right ventricle apex (without connecting with it), compatible with a large apical pseudoaneurysm. The clinical case was discussed in the Heart Team and it was decided to perform cardiac surgery. However, surgical findings showed integrity of septal and free walls, and she underwent an aneurysmectomy, without further complications. Histological examination confirmed the presence of a thin myocardial wall with marked fibrosis and, consequently, the diagnosis of ventricular aneurysm. She was discharged clinically stable and maintains follow-up in Cardiology consultation of our Hospital.

Conclusion

In this patient, initially admitted with an anterior myocardial infarction submitted to primary PCI, follow-up with advanced imaging modalities pointed to the diagnosis of pseudoaneurysm. Despite the preoperative diagnosis, surgical findings were compatible with a giant left ventricular aneurysm. Even with high spatial resolution exams, postoperative evaluation of tissue layers remains the gold standard for this differential diagnosis.

Abstract P871 Figure. Apical pseudoaneurysm vs aneurysm

P918 Screening protocol of patent foramen ovale in cryptogenic stroke

Introduction

Cryptogenic stroke reaches a prevalence of 30% and entails a significant risk of recurrence. Transesophageal echocardiography is the gold standard in identifying potential proximal embolic sources, including patent foramen ovale (PFO). Based on recent evidence, PFO percutaneous closure is recommended in selected cases of cryptogenic stroke, especially if associated with high risk features. Since PFO is present in up to 27% of the general population, the real challenge is to define which patients have a pathogenic PFO.

Purpose

To develop a pathogenic PFO screening protocol in patients with cryptogenic stroke, aimed at secondary prevention.

Methods

We revised the literature, analysing published articles in PubMed in the last 5 years, with the keywords "patent foramen ovale and cryptogenic stroke". Subsequently, we produced a screening algorithm based on cryptogenic stroke definition, on RoPE (Risk of Paradoxical Embolism) Score and on the inclusion and exclusion criteria of the CLOSE, REDUCE and RESPECT studies, which showed promising results of PFO closure in this context.

Results

Our protocol establishes that patients who present with ischemic stroke should be evaluated for risk factors and undergo a detailed etiological study. When the study is inconclusive, the RoPE score is applied to determine the probability of finding a pathogenic or an incidental PFO. If equal or greater than 7 points, in the absence of predefined exclusion criteria, a transesophageal echocardiogram is performed. If the screening is positive, the patient will be referred to the Cardiology Department for therapeutic guidance. If negative, alternative complementary diagnostic methods may be considered.

Conclusion

Through the application of this protocol, patients with high probability of having a pathogenic PFO and, consequently, those who may benefit from percutaneous closure, will be selected to undergo a screening transesophageal echocardiogram. The implementation of a PFO screening protocol in patients who present with cryptogenic stroke is relevant, by proposing to reduce its recurrence rate through the early referral of young patients with indication for an invasive strategy.

Solitary bee pollinators adjust pollen foraging to the unpredictable flower opening of a species of Petunia (Solanaceae)

Details of the foraging patterns of solitary bees are much less well known than those of social species, and these patterns are often adjusted to exploit floral resources of one or only a few species. The specialized flower-visiting bees of Petunia are good models for investigating such foraging patterns. Here we analysed the floral biology and pollen presentation schedule of the endangered Petunia mantiqueirensis in mixed Araucaria forests of Serra da Mantiqueira, Brazil. Pollinators and their pollen foraging behaviour and food specialization were determined through analyses of scopa pollen loads. Flowers opened throughout the day and presented all their pollen resources within the first 30 min of anthesis, thus providing their pollen resources in an asynchronous fashion in one-flower packages throughout the day. Females of Pseudagapostemon fluminensis were the most frequent flower visitors, contacting stigmas in 96% of their visits, and were the unique effective pollinators of Petunia mantiqueirensis. These pollinators were responsible for the first three visits to 115 individually monitored flowers at any daylight hour, removing ~86% of a flower’s total pollen supply during the first visit. Although female bees harvest the majority of pollen resources of Petunia mantiqueirensis, analyses of scopa loads revealed that most of them also collect pollen from plants of other families while foraging for pollen in Petunia flowers.

P879Discharge medication and 1-year outcomes in patients with myocardial infarction and nonobstructive coronary artery disease: a nationwide registry-based study

Introduction

Myocardial infarction with nonobstructive coronary arteries (MINOCA) occurs in 5% to 10% of all patients with myocardial infarction. Although these patients are often treated as if they had obstructive coronary artery disease (OCAD), optimal medical therapy for secondary prevention in MINOCA patients have not been prospectively studied. We hypothesize that the same treatment strategy as for OCAD is unlikely to be beneficial in MINOCA patients due to their heterogeneous nature.

Purpose

Characterize and assess the impact of discharge medication on 1-year mortality or hospitalization in patients with MINOCA.

Methods

Retrospective cohort study of consecutive patients with acute myocardial infarction (AMI) recorded in the Portuguese Registry of Acute Coronary Syndromes (ProACS) between 2010 and 1017. All patients who underwent coronary angiography and had no obstructive lesions (defined as <50% diameter stenosis) were included for analysis (n=829, 4.8% of a total of 17213). Patient demographics, clinical characteristics and medication at discharge were analyzed. The association between treatment and outcome was estimated by comparing treated and untreated groups using Cox proportional hazard models. The exposures considered were treatment at discharge with statins, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARBs), beta-blockers (BB), aspirin (ASA) or dual antiplatelet therapy (DAPT). The outcomes evaluated were 1-year all-cause mortality and 1-year hospitalization due to cardiovascular disease (CVD)

Results

829 patients (54% male, mean age 65±13 years) were included. 67% had hypertension, 20% diabetes mellitus, 45% hyperlipidemia, 66% were overweight, 23% were current smokers, 5.5% had history of heart failure, 4.3% valvular heart disease, 8% cerebrovascular disease and 4.7% chronic kidney disease. The admission diagnosis was most frequently non-ST elevation MI (79.3%) and mean left ventricular ejection fraction (%) was 56±12. 4 patients died during hospitalization (0.5%). At discharge, aspirin was prescribed in 85.7% patients, clopidogrel in 54.8%, ticagrelor in 7.5%, DAPT in 57.7%, ACEi/ARB in 79.2%, beta-blocker in 69% and statins in 90.2%. 1-year mortality and 1-year CVD hospitalization was 3.8% and 9%, respectively. After adjusting for covariates in Cox regression analysis, we found no association between any medication at discharge and 1-year outcomes.

Conclusion

A high proportion of patients are prescribed antiplatelet therapy, including DAPT. We found no significant 1-year beneficial effect of treatment with statins, ACEi/ARBs, BB, aspirin or DAPT in MINOCA. This may be partially explained by the highly heterogenous population and relative short-term follow-up. In MINOCA patients, treatment should be individualized after an exhaustive diagnostic workup to identify the underlying cause (e.g. CAD with spontaneous autolysis of an intracoronary thrombus, myocarditis or takotsubo syndrome).

P1721Determination of a predictive score of cardiogenic shock in acute coronary syndrome

Introduction

Cardiogenic shock is one of the leading causes of death in patients with acute coronary syndrome (ACS), reaching in-hospital mortality rates of 50%.

Purpose

To identify a predictive score of cardiogenic shock in patients with ACS.

Methods

We performed a retrospective, descriptive and correlational study encompassing patients admitted with ACS in a Cardiology service from 1st October 2010 to 1st October 2018. Demographic factors, risk factors, antecedents and clinical characteristics were analyzed. The correlation between the categorical variables was performed by the Chi-square test, while the T-Student test was applied to the continuous variables, with a significance level of 95%. Independent predictors of cardiogenic shock were identified through a binary logistic regression analysis, considering p=0,05. Then, a discriminatory function was applied using the Wilks lambda test to determine the discriminant score of the analized groups. Statistical analysis was conducted with SPSS 24.0.

Results

During this period, 4458 patients were admitted with ACS and 74 (1,7%) developed cardiogenic shock. In this subgroup, 59,5% were over 65 years of age, 63,5% were male and 93,2% presented with acute myocardial infarction with ST segment elevation. Also, 83,8% were in sinus rhythm at admission, 22,7% had creatinine>1,5 mg/dL and 17,9% had left ventricular ejection fraction (LVEF) <30%. The in-hospital mortality rate was 51,4%. LVEF <30% (p=0,018), creatinine>1,5 mg/dL (p=0,044) and absence of sinus rhythm at admission (p=0,041) were independent predictors of cardiogenic shock. A predictive score of this complication in patients with ACS was determined using the formula: 1,723 + 1,505 x (creatinine>1,5) + 4,483 x (LVEF <30%) – 2,094 x (sinus rhythm at admission). A cutoff of 0,58 was obtained with 44,4% sensitivity, 85,2% specificity and 85% discriminative power.

Conclusion

Cardiogenic shock occurred in 1,7% of patients admitted with ACS and was associated with a high mortality rate. We determined a predictive score of this complication with a good discriminative power, which included LVEF <30%, creatinine >1,5 mg/dL and the rhythm on admission's electrocardiogram. By taking into account clinical variables, this score can be used at a very early stage of admission, allowing risk stratification of developing cardiogenic shock in each patient. However, it needs validation to be applied in clinical practice.

P1698Age shock index is a simple bedside clinical risk stratification tool in patients with non-ST-segment elevation myocardial infarction

Introduction

Shock index (SI), (heart rate (HR)/systolic blood pressure (SBP)), has been reported to predict worse outcomes in different acute settings. Two derivatives, named modified SI (MSI), defined as HR/mean BP; and Age SI, defined as SI multiplied by age, were later developed, but only the former was tested for short-term outcomes in patients with myocardial infarction (MI). We hypothesize that Age SI may demonstrate higher prognostic accuracy than SI and MSI due to the added prognostic value of age in this population.

Purpose

Compare the prognostic performance of admission age SI, MSI and SI for predicting in-hospital mortality in patients with NSTEMI.

Methods

Retrospective cohort study of consecutive patients admitted to the Cardiology department of a tertiary care hospital with the diagnosis of NSTEMI between October 2010 and September 2018. Very high-risk patients in need of emergent treatment were excluded. Of the initial cohort of 2476 patients, we excluded 5 who presented cardiac arrest before or at hospital admission, 4 with cardiogenic shock, 95 with acute pulmonary oedema, 10 with SBP <80 mmHg, 1 with HR <40bpm and 1 with HR >160bpm. The primary outcome was all-cause in-hospital mortality. The discriminatory capacity of Age SI, MSI, SI for the primary outcome was assed using the ROC-AUC and compared with the DeLong method, and the value with highest Youden-index was considered the optimal cut-off point. Calibration was assessed using the Hosmer-Lemeshow (HL) test and adjustment for confounding variables was performed using logistic regression analysis.

Results

2359 patients were included [mean age 66±13 years; 1732 (73.4%) men], of whom 40 (1.7%) died during hospitalization. Discrimination by ROC-AUC was highest for Age SI (0.78 [95% CI 0.71–0.86)], compared to MSI (0.69 [95% CI 0.61–0.78]) and SI (0.69 [95% CI 0.61–0.78)], p<0.01 for comparison. All indexes demonstrated adequate calibration (HL: Age SI 7.4; MSI 4.5; SI 6.4; p>0.5). The optimal cut-off for Age SI was 40, which was present in 684 patients (29%) and had 75% sensitivity, 72% specificity, 4.5% positive and 99.5% negative predictive value (NPV) for in-hospital mortality (4.4% vs 0.6%, p<0.001). After adjusting for covariates, an Age SI higher than 40 was associated with increased in-hospital mortality (adjusted OR 3.2, 95% IC 1.06–9.55), p=0.039).

Mortality and Age Shock Index

Conclusion

Age SI demonstrated better discriminatory capacity and equal calibration, compared to SI and MSI for in-hospital mortality. An age SI higher than 40 was associated with a 3-fold increased risk of in-hospital death. This cut-off demonstrated excellent negative predictive value (99.5%) and may allow very early risk assessment in patients with non-ST-segment elevation MI (NSTEMI), before laboratorial values are available for GRACE calculation. This may guide initial therapy and help select the most appropriate initial site of care.

3036Identifying low-risk patients eligible for early discharge after ST-segment elevation myocardial infarction

Introduction

Early discharge after ST-segment elevation myocardial infarction (STEMI) should be considered in low-risk patients after successful percutaneous coronary intervention (PCI) to reduce healthcare costs and improve resource utilization. The Zwolle criteria is recommended by current guidelines for the identification of low-risk patients but a new score, the FASTEST score, has recently demonstrated to add prognostic value over Zwolle score in small and unicentric studies.

Purpose

Assess if FASTEST score could better identify low-risk patients compared to Zwolle in a contemporary nationwide cohort of patients with STEMI who underwent primary PCI and complete revascularization.

Methods

Multicentric observational study of consecutive patients with ACS recorded in the Portuguese Registry of Acute Coronary Syndromes (ProACS) between October 2010 and January 2019. Patients who underwent primary PCI and received complete revascularization were included, and those with missing data for score calculation were excluded. The FASTEST score awards 1 point for each: femoral access, age>65, LVEF<50, TIMI<3; creatinine >1.5 mg/dl; stenosis of the left main coronary artery; and Killip≥2. The Zwolle score was calculated for comparison. The rate of hospital mortality and a composite of serious adverse events (heart failure, cardiogenic shock, re-infarction, mechanical complication, ventricular arrhythmia and major hemorrhage) was compared between low-risk patients as classified by FASTEST (score=0) or Zwolle (score≤3). One-year mortality and cardiovascular rehospitalization was compared between the two groups.

Results

We included 3322 patients (77.4% male, mean age 62±13 years, 49.5% with anterior STEMI). The FASTEST score identified 855 (25.8%) and Zwolle 2353 (70.7%) low-risk patients. Discrimination by AUC for hospital mortality was 0.92 (95% CI 0.91–0.93) for FASTEST score, significantly higher than Zwolle (0.83 (95% CI 0.82–0.84), p<0.001 for comparison) (Fig.1). Overall hospital mortality was 2.8%. 1 patient died in low-risk FASTEST compared to 24 (1%) in low-risk Zwolle (p=0.01). Low-risk Zwolle patients were more likely to suffer serious hospital adverse events compared with FASTEST score low-risk (19.5% vs 8.5%, p<0.001).

At one-year, 1384 patients had follow-up data. Mortality was significantly lower in low-risk FASTEST than Zwolle (1.5% vs 4.6%, p<0.001) and a tendency for less cardiovascular rehospitalization was also noted (5.4% vs 7.5%, p=0.08).

Figure 1. ROC-AUC for hospital mortality

Conclusion

Approximately one in every four patients were classified as low-risk according to FASTEST score, in contrast with 70% for Zwolle score. Low-risk FASTEST score patients exhibited significantly less hospital mortality (1 patient), hospital serious adverse events and 1-year mortality compared with low-risk Zwolle patients. FASTEST score demonstrated better discriminatory capacity for hospital mortality than Zwolle score and its use for risk stratification should be preferred.

P4600Intraventricular conduction disturbance and ventricular paced rhythms in patients with acute coronary syndromes

Introduction

Left or right bundle branch block (LBBB or RBBB) and ventricular paced rhythms (PM) difficult the diagnosis and often delay adequate treatment in patients with acute coronary syndromes (ACS). In the past few years, guidelines have placed a greater emphasis on the need for considering urgent revascularization in these patients.

Purpose

Evaluate initial revascularization strategy and short-term prognostic impact of LBBB, RBBB and PM in patients with ACS.

Methods

Multicentric observational study of consecutive patients with ACS recorded in the Portuguese Registry of Acute Coronary Syndromes (ProACS) between October 2010 and January 2019. Patients were categorized according to the ECG at admission: LBBB, RBBB, PM and normal QRS morphology. Patients with missing data on the ECG or the primary outcome were excluded. Demographic, clinical data and in-hospital outcomes were analyzed. The association between LBBB, RBBB, PM and in-hospital adverse outcomes was assessed using a logistic regression model. The primary and secondary outcomes were in-hospital mortality and a composite of in-hospital adverse events (heart failure, re-infarction or cardiac arrest), respectively.

Results

Of the original cohort, 18314 (94.3%) patients were included (mean age 66±13 years, 73.2% male): 243 (1.3%) had PM, 846 (4.6%) had LBBB, 1195 (6.5%) had RBBB and 16030 (87.5%) had normal QRS. Patients with abnormal QRS were significantly older, had more comorbidities, were less frequently diagnosed as ST-elevation MI (LBBB 18%; RBBB 35.1%; PM 7.8%; Normal 44.2%, p<0.001) and considered for urgent reperfusion (LBBB 13%; RBBB 33.6%; PM 5.8%; Normal 41.6%, p<0.001). Among patients who underwent non-urgent coronary angiography, the finding of an occluded culprit coronary artery was not higher compared to patients with normal QRS (Normal 15.2% vs LBBB 14.3%; RBBB 17.4%; PM 11.4%, p>0.05 for difference).

Overall in-hospital mortality was 3.4% (LBBB 6.6%; RBBB 8.1%; PM 5.3%; Normal 3.4%; p<0.001) and the composite endpoint of in-hospital adverse events was 17.4% (LBBB 35.6%; RBBB 27.3%; PM 23.5%; Normal 15.6%, p<0.001). After adjusting for cofounding variables, and using normal QRS as reference, only RBBB was shown to be significantly associated with increased in-hospital mortality (OR 1.94; 95% CI 1.43–2.66), p<0.001); and both RBBB (OR 1.75; 95% CI 1.5–2, p<0.001) and LBBB (OR 1.8; 95% CI 1.4–2.3, p<0.001), but not PM, were significantly associated with the composite endpoint of heart failure, re-infarction or cardiac arrest.

Conclusion

Compared to patients with normal QRS, those with LBBB, RBBB or PM less often undergo urgent revascularization and have higher rates of in-hospital adverse outcomes. In multivariate analysis, RBBB patients are almost two times more likely to die compared to those with normal QRS. LBBB and RBBB were independently associated with increased rates of in-hospital adverse events. PM was not associated with worse in-hospital outcomes.

Bimodal Patterning Discrimination in Harnessed Honey Bees

In natural environments, stimuli and events learned by animals usually occur in a combination of more than one sensory modality. An important problem in experimental psychology has been thus to understand how organisms learn about multimodal compounds and how they discriminate this compounds from their unimodal constituents. Here we tested the ability of honey bees to learn bimodal patterning discriminations in which a visual-olfactory compound (AB) should be differentiated from its visual (A) and olfactory (B) elements. We found that harnessed bees trained in classical conditioning of the proboscis extension reflex (PER) are able to solve bimodal positive and negative patterning (NP) tasks. In positive patterning (PP), bees learned to respond significantly more to a bimodal reinforced compound (AB+) than to non-reinforced presentations of single visual (A-) or olfactory (B-) elements. In NP, bees learned to suppress their responses to a non-reinforced compound (AB-) and increase their responses to reinforced presentations of visual (A+) or olfactory (B+) elements alone. We compared the effect of two different inter-trial intervals (ITI) in our conditioning approaches. Whereas an ITI of 8 min allowed solving both PP and NP, only PP could be solved with a shorter ITI of 3 min. In all successful cases of bimodal PP and NP, bees were still able to discriminate between reinforced and non-reinforced stimuli in memory tests performed one hour after conditioning. The analysis of individual performances in PP and NP revealed that different learning strategies emerged in distinct individuals. Both in PP and NP, high levels of generalization were found between elements and compound at the individual level, suggesting a similar difficulty for bees to solve these bimodal patterning tasks. We discuss our results in light of elemental and configural learning theories that may support the strategies adopted by honey bees to solve bimodal PP or NP discriminations.

Visual discrimination transfer and modulation by biogenic amines in honeybees

For more than a century, visual learning and memory has been studied in the honeybee Apis mellifera using operant appetitive conditioning. Although honeybees show impressive visual learning capacities in this well-established protocol, operant training of free-flying animals can hardly be combined with invasive protocols for studying the neurobiological basis of visual learning. In view of that, different efforts have been made to develop new classical conditioning protocols for studying visual learning in harnessed honeybees, though learning performances remain considerably poorer than those obtained in free-flying animals. Here we investigated the ability of honeybees to use visual information acquired during classical conditioning in a new operant context. We performed differential visual conditioning of the proboscis extension reflex (PER) followed by visual orientation tests in Y-maze. Classical conditioning and Y-maze retention tests were performed using a same pair of perceptually isoluminant monochromatic stimuli, to avoid the influence of phototaxis during free-flying orientation. Visual discrimination transfer was clearly observed, with pre-trained honeybees significantly orienting their flights towards the former positive conditioned stimulus (CS+). We thus show that visual memories acquired by honeybees are resistant to context changes between conditioning and retention test. We combined this visual discrimination approach with selective pharmacological injections to evaluate the effect of dopamine and octopamine in appetitive visual learning. Both octopaminergic and dopaminergic antagonists impaired visual discrimination performances, suggesting that both these biogenic amines modulate appetitive visual learning in honeybees. Our study brings new insights into cognitive and neurobiological mechanisms underlying visual learning in honeybees.

Treatment of alcoholism – New targets?

Introduction

Alcohol use disorders (AUD) is a preventable cause of significant morbidity and mortality worldwide. AUD is a heterogeneous disorder stemming from a complex interaction of neurobiological, genetic, and environmental factors. To achieve treatment effectiveness this heterogenity should be considered, as well as safety.

Objectives

Review mechanisms underlying alcohol addiction in order to work out new, more effective treatment strategies.

Aim

To update on treatment for alcoholism.

Methods

A literature search was performed on PubMed database.

Results

Alcohol dependence is a chronic, relapsing condition in which there is evidence of significant change in the motivation and control systems in the brain. Increasingly drug therapy is focused not just on the treatment of the acute withdrawal syndrome, but on modifying these other dysregulated brain systems. Of the numerous neurotransmitter systems that have been identified for the development of new medicines, the most promising compounds appear to be those that modulate the function of opioids, glutamate with or without gamma-aminobutyric acid, and serotonin. Other putative therapeutic medications including direct modulators of dopamine function and enzyme inhibitors also shall be discussed. At present, only four medications are approved for the treatment of alcohol dependence in Europe, that is naltrexone, acamprosate, disulfiram and the most recent nalmefene. Among other promising strategies the following drugs are mentioned: baclofen, topiramate, ondansetron, aripiprazole, rimonabant and varenicline.

Conclusions

Pharmacological development remains a high priority in the alcoholism field. Drugs have different safety profiles that need to be balanced with the treatment objective, individual patient preferences and comorbid conditions.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Do not forget alcohol damage – Cognitive impairments related to alcohol

Introduction

Chronic excessive alcohol consumption may lead to structural and functional damage of the brain. Alcohol-related cognitive impairments are well-established and confirmed by neuropsychological and neuroimaging studies. However, the influence of each neuropathological mechanisms is still under discussion. This topic is increasingly becoming focus of attention in psychiatry.

Objectives

Review the neuropathology, clinical features, neuropsychology and management of alcohol-related cognitive impairments.

Aims

Evaluate clinical impact, management and prognosis of alcohol-related cognitive impairments.

Methods

A literature search was performed on PubMed and Medscape database.

Results

According to our literature research, there is a debate concerning the relative contributions of the direct toxic effect of alcohol and the impact of thiamine deficiency on the alcohol-related cognitive impairments. Research about this issue is challenging, considering the multiple patterns of alcohol abuse, the personal and lifestyle factors, and the vulnerability of specific brain regions. The cognitive decline is linked to neuroanatomical alterations and primarily affects executive functions, episodic memory, and visuospatial capacities. These deficits may range from mild to severe but usually remain undiagnosed, unless they are specifically investigated. Maintenance of lasting abstinence is associated with cognitive recovery, but some impairments may persist and interfere with the prognosis.

Conclusion

Recognizing and screening for alcohol-related cognitive impairments is crucial to offer significant benefits to patients by optimising management strategies.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Advances and limitations of visual conditioning protocols in harnessed bees

Bees are excellent invertebrate models for studying visual learning and memory mechanisms, because of their sophisticated visual system and impressive cognitive capacities associated with a relatively simple brain. Visual learning in free-flying bees has been traditionally studied using an operant conditioning paradigm. This well-established protocol, however, can hardly be combined with invasive procedures for studying the neurobiological basis of visual learning. Different efforts have been made to develop protocols in which harnessed honey bees could associate visual cues with reinforcement, though learning performances remain poorer than those obtained with free-flying animals. Especially in the last decade, the intention of improving visual learning performances of harnessed bees led many authors to adopt distinct visual conditioning protocols, altering parameters like harnessing method, nature and duration of visual stimulation, number of trials, inter-trial intervals, among others. As a result, the literature provides data hardly comparable and sometimes contradictory. In the present review, we provide an extensive analysis of the literature available on visual conditioning of harnessed bees, with special emphasis on the comparison of diverse conditioning parameters adopted by different authors. Together with this comparative overview, we discuss how these diverse conditioning parameters could modulate visual learning performances of harnessed bees.

Synaptic Organization of Microglomerular Clusters in the Lateral and Medial Bulbs of the Honeybee Brain

The honeybee Apis mellifera is an established model for the study of visual orientation. Yet, research on this topic has focused on behavioral aspects and has neglected the investigation of the underlying neural architectures in the bee brain. In other insects, the anterior optic tubercle (AOTU), the lateral (LX) and the central complex (CX) are important brain regions for visuospatial performances. In the central brain of the honeybee, a prominent group of neurons connecting the AOTU with conspicuous microglomerular synaptic structures in the LX has been recently identified, but their neural organization and ultrastructure have not been investigated. Here we characterized these microglomerular structures by means of immunohistochemical and ultrastructural analyses, in order to evaluate neurotransmission and synaptic organization. Three-dimensional reconstructions of the pre-synaptic and post-synaptic microglomerular regions were performed based on confocal microscopy. Each pre-synaptic region appears as a large cup-shaped profile that embraces numerous post-synaptic profiles of GABAergic tangential neurons connecting the LX to the CX. We also identified serotonergic broad field neurons that probably provide modulatory input from the CX to the synaptic microglomeruli in the LX. Two distinct clusters of microglomerular structures were identified in the lateral bulb (LBU) and medial bulb (MBU) of the LX. Although the ultrastructure of both clusters is very similar, we found differences in the number of microglomeruli and in the volume of the pre-synaptic profiles of each cluster. We discuss the possible role of these microglomerular clusters in the visuospatial behavior of honeybees and propose research avenues for studying their neural plasticity and synaptic function.

Hereditary influence in alcohol dependence

Introduction

Alcohol dependence is one of the psychiatric disorders for which hereditary influence is strongest. In fact, the importance of genetic factors in transmission of vulnerability to alcohol dependence was first described in literature many years ago by psychiatrists who dedicate to its study. That vulnerability may be explained by an epigenetic model in which biological hereditary factors associate with environmental factors to cause alcohol dependence.

Objectives

Study the influence of genetic factors on alcohol dependence.

Methods

During 4 consecutive months a sample of alcoholic patients was collected from the Alcohol Treatment Unit of CHPL (inpatients and outpatients). Biographic data, patient's psychiatric diagnosis and family history of alcohol dependence or of dependence of other drugs were recorded.

Results

Initial sample included 122 patients. After exclusion of patients who were also hospitalized in that period, the final sample included 102 patients (26% female), with a mean age of 48 years old. Main patients’ diagnosis was alcohol dependence but most of them (52%) presented psychiatric comorbidity. Most patients (55%) had family history of alcohol dependence or dependence of other substances, 26% did not have and 19% did not know. For 61% of patients, the father and/or mother were the affected relative. Most patients (61%) who had a family history of alcohol dependence or dependence of other substances had 2 or more affected relatives.

Conclusions

Most patients with alcohol dependence have family history of alcohol dependence or dependence of other substances, usually in more than 1 relative, which must be taken in account during treatment.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

A multi-species bait for Chagas disease vectors

Background

Triatomine bugs are the insect vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. These insects are known to aggregate inside shelters during daylight hours and it has been demonstrated that within shelters, the aggregation is induced by volatiles emitted from bug feces. These signals promote inter-species aggregation among most species studied, but the chemical composition is unknown.

Methodology/Principal Findings

In the present work, feces from larvae of the three species were obtained and volatile compounds were identified by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). We identified five compounds, all present in feces of all of the three species: Triatoma infestans, Panstrongylus megistus and Triatoma brasiliensis. These substances were tested for attractivity and ability to recruit insects into shelters. Behaviorally active doses of the five substances were obtained for all three triatomine species. The bugs were significantly attracted to shelters baited with blends of 160 ng or 1.6 µg of each substance.

Conclusions/Significance

Common compounds were found in the feces of vectors of Chagas disease that actively recruited insects into shelters, which suggests that this blend of compounds could be used for the development of baits for early detection of reinfestation with triatomine bugs.

Chagas disease is a parasitic infection affecting approximately 12 million people, and is considered to be one of the most severe burdens for public health in Latin America. Control of the disease is based on attempted elimination of domestic populations of triatomine bugs, the insects transmitting the disease to humans, by means of insecticide spraying. Currently, vigilance programs monitoring triatomine reinfestation processes in houses are performed by manual search for bugs. Effective and sustainable new methods allowing continuous monitoring of domestic triatomine populations are required. Based on the fact that the insects hide in dark refuges that are marked by volatile signals emitted in their feces, we screened the feces of three species for volatile compounds common to these prominent vectors. The potential for these odors to promote triatomine aggregation was evaluated and we present evidence that a synthetic blend of these substances is capable of recruiting bugs into shelters, mimicking the natural pheromone. This blend may be used to develop a bait to monitor triatomine reinfestation processes in a similar manner as is used commonly for the monitoring of agricultural pests.

Genetic basis of triatomine behavior: lessons from available insect genomes

Triatomines have been important model organisms for behavioural research. Diverse reports about triatomine host search, pheromone communication in the sexual, shelter and alarm contexts, daily cycles of activity, refuge choice and behavioural plasticity have been published in the last two decades. In recent times, a variety of molecular genetics techniques has allowed researchers to investigate elaborate and complex questions about the genetic bases of the physiology of insects. This, together with the current characterisation of the genome sequence of Rhodnius prolixus allows the resurgence of this excellent insect physiology model in the omics era. In the present revision, we suggest that studying the molecular basis of behaviour and sensory ecology in triatomines will promote a deeper understanding of fundamental aspects of insect and, particularly, vector biology. This will allow uncovering unknown features of essential insect physiology questions for a hemimetabolous model organism, promoting more robust comparative studies of insect sensory function and cognition.

Lack of segregation between two species of Chagas disease vectors

Triatoma infestans and Panstrongylus megistus are relevant Chagas disease vectors. An apparent segregation among these triatomine species inside human households was suggested to rely on mutual repellence between them. However, P. megistus and T. infestans show aggregation responses to chemical signals emitted by the other species. These findings do not rule out the possibility that stimuli other than chemical signals could mediate repellence when these species exploit shelters simultaneously. In the present study, we investigated how P. megistus and T. infestans exploit shelters in controlled laboratory conditions and how insect density and environmental illumination modulate this behavior. We evaluated whether these species aggregate inside shelters or mutually repel each other. Panstrongylus megistus and T. infestans show specific patterns of shelter exploitation, which are differentially affected by insect density and environment illumination. In particular, P. megistus is more sensitive to insect density than T. infestans, whereas T. infestans shows higher sensitivity to illumination than P. megistus. Nevertheless, these species exploit shelters randomly without any apparent repellence.

Visual conditioning of the sting extension reflex in harnessed honeybees

Visual performances of honeybees have been extensively studied using free-flying individuals trained to choose visual stimuli paired with sucrose reward. By contrast, harnessed bees in the laboratory were not thought to be capable of learning a Pavlovian association between a visual stimulus (CS) and sucrose reward (US). For reasons as yet unknown, harnessed bees only learn visual cues in association with sucrose if their antennae are ablated. However, slow acquisition and low retention performances are obtained in this case. Here, we established a novel visual conditioning protocol, which allows studying visual learning and memory in intact harnessed bees in the laboratory. This protocol consists of conditioning the sting extension reflex (SER) by pairing a visual stimulus (CS+) with an electric shock punishment (US), and a different visual stimulus (CS–) with the absence of shock. Bees with intact antennae learned the discrimination between CS+ and CS– by using chromatic cues, achromatic cues or both. Antennae ablation was not only unnecessary for learning to occur but it even impaired visual SER conditioning because of a concomitant reduction of responsiveness to the electric shock. We thus established the first visual conditioning protocol on harnessed honeybees that does not require injuring the experimental subjects. This novel experimental approach opens new doors for accessing the neural correlates of visual learning and memory in honeybees.

Neural organization and visual processing in the anterior optic tubercle of the honeybee brain

The honeybee Apis mellifera represents a valuable model for studying the neural segregation and integration of visual information. Vision in honeybees has been extensively studied at the behavioral level and, to a lesser degree, at the physiological level using intracellular electrophysiological recordings of single neurons. However, our knowledge of visual processing in honeybees is still limited by the lack of functional studies of visual processing at the circuit level. Here we contribute to filling this gap by providing a neuroanatomical and neurophysiological characterization at the circuit level of a practically unstudied visual area of the bee brain, the anterior optic tubercle (AOTu). First, we analyzed the internal organization and neuronal connections of the AOTu. Second, we established a novel protocol for performing optophysiological recordings of visual circuit activity in the honeybee brain and studied the responses of AOTu interneurons during stimulation of distinct eye regions. Our neuroanatomical data show an intricate compartmentalization and connectivity of the AOTu, revealing a dorsoventral segregation of the visual input to the AOTu. Light stimuli presented in different parts of the visual field (dorsal, lateral, or ventral) induce distinct patterns of activation in AOTu output interneurons, retaining to some extent the dorsoventral input segregation revealed by our neuroanatomical data. In particular, activity patterns evoked by dorsal and ventral eye stimulation are clearly segregated into distinct AOTu subunits. Our results therefore suggest an involvement of the AOTu in the processing of dorsoventrally segregated visual information in the honeybee brain.

Color modulates olfactory learning in honeybees by an occasion-setting mechanism

A sophisticated form of nonelemental learning is provided by occasion setting. In this paradigm, animals learn to disambiguate an uncertain conditioned stimulus using alternative stimuli that do not enter into direct association with the unconditioned stimulus. For instance, animals may learn to discriminate odor rewarded from odor nonrewarded trials if these two situations are indicated by different colors that do not themselves become associated with the reward. Despite a growing interest in nonelemental learning in insects, no study has so far attempted to study occasion setting in restrained honeybees, although this would allow direct access to the neural basis of nonelemental learning. Here we asked whether colors can modulate olfactory conditioning of the proboscis extension reflex (PER) via an occasion-setting mechanism. We show that intact, harnessed bees are not capable of learning a direct association between color and sucrose. Despite this incapacity, bees solved an occasion-setting discrimination in which colors set the occasion for appropriate responding to an odor that was rewarded or nonrewarded depending on the color. We therefore provide the first controlled demonstration of bimodal (color-odor) occasion setting in harnessed honeybees, which opens the door for studying the neural basis of such bimodal, nonelemental discriminations in insects.

Multiple reversal olfactory learning in honeybees

In multiple reversal learning, animals trained to discriminate a reinforced from a non-reinforced stimulus are subjected to various, successive reversals of stimulus contingencies (e.g. A+ vs. B−, A− vs. B+, A+ vs. B−). This protocol is useful to determine whether or not animals “learn to learn” and solve successive discriminations faster (or with fewer errors) with increasing reversal experience. Here we used the olfactory conditioning of proboscis extension reflex to study how honeybees Apis mellifera perform in a multiple reversal task. Our experiment contemplated four consecutive differential conditioning phases involving the same odors (A+ vs. B− to A− vs. B+ to A+ vs. B− to A− vs. B+). We show that bees in which the weight of reinforced or non-reinforced stimuli was similar mastered the multiple olfactory reversals. Bees which failed the task exhibited asymmetric responses to reinforced and non-reinforced stimuli, thus being unable to rapidly reverse stimulus contingencies. Efficient reversers did not improve their successive discriminations but rather tended to generalize their choice to both odors at the end of conditioning. As a consequence, both discrimination and reversal efficiency decreased along experimental phases. This result invalidates a learning-to-learn effect and indicates that bees do not only respond to the actual stimulus contingencies but rather combine these with an average of past experiences with the same stimuli.

Profiling of colour pigments of chili powders of different origin by high-performance liquid chromatography

The colour pigments of five chili powders of different origins were separated and quantified by reversed-phase high-performance liquid chromatography (RP-HPLC). The similarities and dissimilarities of pigment composition of chili powders were elucidated by principal component analysis (PCA). RP-HPLC separated 50-100 pigment fractions depending on the detection wavelength and on the origin of chili powder. It was found that the pigment composition of chili powders from Malaysia and China and from India and Pakistan show marked similarities while the composition of colour pigments of chili powder from Thailand was different. It was further established that the chromatograms are similar in the first 5-35 min of development, they are highly different between 35 and 75 min and moderately different at the end of the chromatograms. It was concluded that RP-HPLC followed by PCA can be successfully used for the identification of chili powders according to the composition of their colour pigments.

[Inhibition of renin-angiotensin-aldosterone system: what evidence?]

The activation of various neuro-humoral systems is involved in the progression of chronic heart failure. The pharmacological blockade of the renin-angiotensin-aldosterone system is possible with agents such as angiotensin converting enzyme inhibitors (ACEI), the angiotensin II receptor antagonists (ARA) and the aldosterone antagonists. The actual scientific evidence supports the use of the ACEI in patient with ventricular dysfunction in all functional NYHA classes, of the ARA in heart failure patients with intolerance to ACEI and of low-dose spironolactone in patients with severe heart failure. Ongoing clinical trials will further clarify the role of these pharmacological agents in the management of chronic heart failure patients.

Separation and quantitation of colour pigments of chili powder (Capsicum frutescens) by high-performance liquid chromatography-diode array detection

The performance of reversed-phase thin-layer (RP-TLC) and reversed-phase high-performance liquid chromatography (RP-HPLC) was compared for the separation and determination of the colour pigments of chili (Capsicum frutescens) powder using a wide variety of eluent systems. No separation of pigments was achieved in RP-TLC, however, it was established that tetrahydrofuran shows an unusually high solvent strength. RP-HPLC using water-methanol-acetonitrile gradient elution separated the chili pigments in many fractions. Diode array detection (DAD) indicated that yellow pigments are eluted earlier than the red ones and chili powder contains more yellow pigments than common paprika powders. It was established that the very different absorption spectra of pigments make the use of DAD necessary.