An individual-based model to explore the impact of psychological stress on immune infiltration into tumour spheroids

In recentin vitroexperiments on co-culture between breast tumour spheroids and activated immune cells, it was observed that the introduction of the stress hormone cortisol resulted in a decreased immune cell infiltration into the spheroids. Moreover, the presence of cortisol deregulated the normal levels of the pro- and anti-inflammatory cytokines IFN-γand IL-10. We present an individual-based model to explore the interaction dynamics between tumour and immune cells under psychological stress conditions. With our model, we explore the processes underlying the emergence of different levels of immune infiltration, with particular focus on the biological mechanisms regulated by IFN-γand IL-10. The set-up of numerical simulations is defined to mimic the scenarios considered in the experimental study. Similarly to the experimental quantitative analysis, we compute a score that quantifies the level of immune cell infiltration into the tumour. The results of numerical simulations indicate that the motility of immune cells, their capability to infiltrate through tumour cells, their growth rate and the interplay between these cell parameters can affect the level of immune cell infiltration in different ways. Ultimately, numerical simulations of this model support a deeper understanding of the impact of biological stress-induced mechanisms on immune infiltration.

Evolutionary dynamics of glucose-deprived cancer cells: insights from experimentally informed mathematical modelling

Glucose is a primary energy source for cancer cells. Several lines of evidence support the idea that monocarboxylate transporters, such as MCT1, elicit metabolic reprogramming of cancer cells in glucose-poor environments, allowing them to re-use lactate, a by-product of glucose metabolism, as an alternative energy source with serious consequences for disease progression. We employ a synergistic experimental and mathematical modelling approach to explore the evolutionary processes at the root of cancer cell adaptation to glucose deprivation, with particular focus on the mechanisms underlying the increase in MCT1 expression observed in glucose-deprived aggressive cancer cells. Data from in vitro experiments on breast cancer cells are used to inform and calibrate a mathematical model that comprises a partial integro-differential equation for the dynamics of a population of cancer cells structured by the level of MCT1 expression. Analytical and numerical results of this model suggest that environment-induced changes in MCT1 expression mediated by lactate-associated signalling pathways enable a prompt adaptive response of glucose-deprived cancer cells, while fluctuations in MCT1 expression due to epigenetic changes create the substrate for environmental selection to act upon, speeding up the selective sweep underlying cancer cell adaptation to glucose deprivation, and may constitute a long-term bet-hedging mechanism.

Predictive Potential of Cmax Bioequivalence in Pilot Bioavailability/Bioequivalence Studies, through the Alternative ƒ2 Similarity Factor Method

Pilot bioavailability/bioequivalence (BA/BE) studies are downsized trials that can be conducted prior to the definitive pivotal trial. In these trials, 12 to 18 subjects are usually enrolled, although, in principle, a sample size is not formally calculated. In a previous work, authors recommended the use of an alternative approach to the average bioequivalence methodology to evaluate pilot studies' data, using the geometric mean (Gmean) ƒ2 factor with a cut off of 35, which has shown to be an appropriate method to assess the potential bioequivalence for the maximum observed concentration (Cmax) metric under the assumptions of a true Test-to-Reference Geometric Mean Ratio (GMR) of 100% and an inter-occasion variability (IOV) in the range of 10% to 45%. In this work, the authors evaluated the proposed ƒ2 factor in comparison with the standard average bioequivalence in more extreme scenarios, using a true GMR of 90% or 111% for truly bioequivalent formulations, and 80% or 125% for truly bioinequivalent formulations, in order to better derive conclusions on the potential of this analysis method. Several scenarios of pilot BA/BE crossover studies were simulated through population pharmacokinetic modelling, accounting for different IOV levels. A redefined decision tree is proposed, suggesting a fixed sample size of 20 subjects for pilot studies in the case of intra-subject coefficient of variation (ISCV%) > 20% or unknown variability, and suggesting the assessment of study results through the average bioequivalence analysis, and additionally through Gmean ƒ2 factor method in the case of the 90% confidence interval (CI) for GMR is outside the regulatory acceptance bioequivalence interval of [80.00-125.00]%. Using this alternative approach, the certainty levels to proceed with pivotal studies, depending on Gmean ƒ2 values and variability scenarios tested (20-60% IOV), were assessed, which is expected to be helpful in terms of the decision to proceed with pivotal bioequivalence studies.

Preliminary evidence that Merkel cells exert chemosensory functions in human epidermis

The mechanotransduction of light-touch sensory stimuli is considered to be the main physiological function of epidermal Merkel cells (MCs). Recently, however, MCs have been demonstrated to be also thermo-sensitive, suggesting that their role in skin physiologically extends well beyond mechanosensation. Here, we demonstrate that in healthy human skin epidermal MCs express functional olfactory receptors, namely OR2AT4, just like neighbouring keratinocytes. Selective stimulation of OR2AT4 by topical application of the synthetic odorant, Sandalore®, significantly increased Piccolo protein expression in MCs, as assessed by quantitative immunohistomorphometry, indicating increased vesicle trafficking and recycling, and significantly reduced nerve growth factor (NGF) immunoreactivity within MCs, possibly indicating increased neurotrophin release upon OR2AT4 activation. Live-cell imaging showed that Sandalore® rapidly induces a loss of FFN206-dependent fluorescence in MCs, suggesting OR2AT4-dependent MC depolarization and subsequent vesicle secretion. Yet, in contrast to keratinocytes, OR2AT4 stimulation by Sandalore® altered neither the number nor the proliferation status of MCs. These preliminary ex vivo findings demonstrate that epidermal MCs also exert OR-dependent chemosensory functions in human skin, and invite one to explore whether these newly identified properties are dysregulated in selected skin disorders, for example, in pruritic dermatoses, and if these novel MC functions can be therapeutically targeted to maintain/promote skin health.

Productivity gains in vegetables from rice husk biochar application in nutrient-poor soils in Timor-Leste

Response to fertilisation with biochar is greatest in field crops on acidic tropical soils, but limited information is available for vegetable crops. As a case-study using vegetable production in Timor-Leste, we assessed if biochar alleviates nutritional constraints to vegetables in low-nutrient soils. Field trials on vegetable crops were conducted with fertiliser combinations of rice husk biochar, phosphate and local fertiliser at three sites. A pot soil incubation trial of biochar was undertaken with soil from the acid site, where rice husk biochar had a larger effect on productivity than the other fertilisers in chili pepper, tomato and soybean with an average yield increase with biochar of 230% over control. Combining phosphate with biochar augmented the yield over biochar alone in chili pepper, tomato and soybean. At neutral and alkaline sites, fertilisation with biochar lifted mean yield over the control. Soil constraints alleviated by fertiliser were primarily from P and Zn deficiencies. Marked increases in vegetable yields, among the highest globally, were achieved with fertilisation with biochar individually and in combination with phosphate in low nutrient soil in Timor-Leste. Clearly, rice husk biochar is a promising avenue to fertilise the soil with P and Zn and increase crop productivity in Timor-Leste.

Managing Nanomaterials in the Workplace by Using the Control Banding Approach

Nanomaterials offer new technical and commercial opportunities. However, they may also pose risks to consumers and the environment and raise concerns about occupational health and safety. An overview of the standardization in the area of nanomaterials is presented. Focus is given to the standard ISO/TS 12901-2:2014, which describes the use of a control banding approach for controlling the risks associated with occupational exposures to nano-objects and their aggregates and agglomerates greater than 100 nm. The article also presents a case study on a textile finishing company that implements two chemical finishes containing nanomaterials. A risk analysis was conducted to assess the hazards associated with workers handling nanomaterials. Control banding was applied, and measures such as appropriate ventilation and use of protective equipment are proposed to mitigate risks. In some cases, additional measures, such as a closed booth and smoke extractor, are required. The safety data sheets are a primary source of information on how to handle and care for products containing nanomaterials, but the information provided is still limited in terms of the specific hazards and risks posed by nanomaterials.

Short-term outcomes in patients with non-ST-segment elevation myocardial infarction

Funding Acknowledgements

Type of funding sources: None.

Introduction

The proportion of non-ST-segment elevation myocardial infarction (NSTEMI) is increasing among the acute coronary syndromes (ACS). Reinfarction (RI) is a potential complication in high-risk patients with NSTEMI and it will cause an impact on these patients’ prognosis.

Purpose

Identify high-risk patients with RI and their prognosis in the setting of NSTEMI.

Methods

Based on a multicenter retrospective study, data collected from admissions between January 2013 and January 2020. Patients without data on previous cardiovascular history or uncompleted clinical data were excluded. Patients were divided in 2 groups (G): G1 – patients without RI; G2 - patients with RI during hospitalization. Logistic regression and survival analysis were performed.

Results

7180 patients were admitted with NSTEMI, RI occurred in 71 pts (0.99%). Regarding epidemiological and past history G2 was older (71±12 vs 66±12, p=0.001), had higher rates of previous stroke (15.9% vs 7.0%, p 0.003) and peripheric arterial disease (6.3% vs 6.1%, p=0.004). The groups were similar regarding arterial hypertension (p=0.74), diabetes type 2 (p=0.11) and dyslipidaemia (p=0.48).

G2 had higher levels of brain natriuretic peptide (45.5% vs 24.5%, p<0.001) and lower levels of haemoglobin (20.3% vs 7.9%, p<0.001). Patients taking prasugrel (2% vs 0.3%, p=0.002) or ticagrelor (6.1% vs 2.2%, p<0.001) previously to the admission were more susceptible to have RI. Patients with severe left ventricular systolic dysfunction (3.4% vs 2.6%, p<0.001), need of invasive (2.8% vs 0.8%, p<0.001) or non-invasive (4.2% vs 1.3%, p<0.001) ventilation and percutaneous coronary intervention (PCI) (80.3% vs 64.7%, p0.006) had higher rates of RI.

Logist regression confirmed that PCI (p=0.03, OR 2.22, CI 1.08-4.53), previous stroke (p=0.02, OR 0.58, CI 0.37-0.92) and pts previously taking prasugrel (p=0.02, OR 1.85, CI 1.11-3.10) were predictors of RI in the setting of NSTEMI.

Conclusion

RI in the setting of NSTEMI was associated with PCI, previous stroke and pts previously taking prasugrel. One year prognosis was poorer for patients who suffered RI.

Can we prevent the occurrence of stroke in patients admitted with non-ST-segment elevation myocardial infarction?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Cardio-cerebral vascular diseases are a leading cause of deaths worldwide.

Stroke is a potential complication in high-risk patients who had non-ST-segment elevation myocardial infarction (NSTEMI).

Purpose

Identify high-risk patients with stroke and their prognosis in the setting of NSTEMI.

Methods

Based on a multicenter retrospective study, data collected from admissions between January 2013 and January 2020. Patients without data on previous cardiovascular history or uncompleted clinical data were excluded. Patients were divided in 2 groups (G): G1 – patients who suffered stroke; G2 - patients without stroke. Logistic regression and survival analysis were performed.

Results

7180 patients were admitted with NSTEMI, stroke occurred in 35 patients (0.49%). Regarding epidemiological and past history G1 was older (72±9 vs 66±12, p= 0.004), had more females (54.3% vs 45.75, p<0.001), had higher rates of type 2 diabetes mellitus (51.3% vs 35.2%, p=0.05), previous strokes / transient ischemic attack (24.2% vs 7.0%, p=0.007) and dementia (3.3% vs 0.8%, p<0.001). Arterial hypertension (77.1 vs 72.8%, p=0.56), dyslipidaemia (61.8% vs 63.0%, p=0.88) and smoking (17.6% vs 26.0%, p=0.27) were similar between groups. Patients who presented with chest pain (72.7% vs 92.0%, p<0.001) and patients who were not revascularized were more likely to suffer a stroke (43.3% vs 17.5%, p<0.001).

Logist regression only confirmed that females were more likely to have a stroke (p<0.001, OR 4.13, CI 1.87-9.15) and patients who presented with chest pain (p=0.001, OR 0.23, CI 0.10-0.54). One year event-free survival was higher in patients who did not have stroke (95.3% vs 80.0%, p=0.005, OR 4.50, CI 1.43-14.15)

Conclusion

Since sex gender and form of presentation of NSTEMI are not modifiable factors we cannot prevent strokes from happening in the context of NSTEMI.

Extending MQTT with Real-Time Communication Services Based on SDN

MQTT is one of the most popular application-layer protocols used in the scope of the Internet-of-Things (IoT) and Industrial-Internet-of-Things (IIoT), given its suitability for resource-constrained embedded systems. However, MQTT Quality-of-Service policies do not support timeliness requirements, which is common in IIoT. The literature reports several research works that address this limitation, but they are limited in scope (e.g., improvements in the broker’s internal operation, control of the publisher’s data rate, and path optimizations). Conversely, this paper presents a comprehensive architectural approach, proposing a set of extensions to the MQTT protocol that allow applications to explicitly specify real-time requirements and instantiate corresponding network reservations to enforce the desired temporal behavior. Such reservations are enforced via Software Defined Networking, specifically the OpenFlow protocol, but other protocols that allow bandwidth reservations, e.g., TSN, can also be used. This paper presents the proposed system architecture together with extensive emulation and implementation results that validate the feasibility of the approach, showing that time-sensitive MQTT traffic can be effectively segregated and prioritized to meet application-defined real-time requirements. Using several combinations of network topologies and load levels and comparing to the absence of the proposed real-time mechanisms, both average and worst-case latencies of the time-sensitive traffic decreased to approximately half, while for the normal traffic, they increased by approximately 10%.

Optimal Relay Network for Aerial Remote Inspections

Unmanned aerial vehicles (UAVs), in particular multirotors, are becoming the de facto tool for aerial sensing and remote inspection. In large industrial facilities, a UAV can transmit an online video stream to inspect difficult-to-access structures, such as chimneys, deposits, and towers. However, the communication range is limited, constraining the UAV operation range. This limitation can be overcome with relaying UAVs placed between the source UAV and the control station, creating a line of communication links. In this work, we assume the use of a digital data packet network technology, namely WiFi, and tackle the problem of defining the exact placement for the relaying UAVs that creates an end-to-end channel with maximal delivery of data packets. We consider asymmetric communication links and we show an increase as large as 15% in end-to-end packet delivery ratio when compared to an equidistant placement. We also discuss the deployment of such a network and propose a fully distributed method that converges to the global optimal relay positions taking, on average, 1.4 times the time taken by a centralized method.

Usability of a telehealth solution based on TV interaction for the elderly: the VITASENIOR-MT case study

Remote monitoring of biometric data in the elderly population is an important asset for improving the quality of life and level of independence of elderly people living alone. However, the design and implementation of health technological solutions often disregard the elderly physiological and psychological abilities, leading to low adoption of these technologies. We evaluate the usability of a remote patient monitoring solution, VITASENIOR-MT, which is based on the interaction with a television set. Twenty senior participants (over 64 years) and a control group of 20 participants underwent systematic tests with the health platform and assessed its usability through several questionnaires. Elderly participants scored high on the usability of the platform, very close to the evaluation of the control group. Sensory, motor and cognitive limitations were the issues that most contributed to the difference in usability assessment between the elderly group and the control group. The solution showed high usability and acceptance regardless of age, digital literacy, education and impairments (sensory, motor and cognitive), which shows its effective viability for use and implementation as a consumer product in the senior market.

Untangling Absorption Mechanisms and Variability in Bioequivalence Studies Using Population Analysis

PURPOSE

Both inter-individual (IIV) and inter-occasion (IOV) variabilities are observed in bioequivalence studies. High IOV may be a cause of problems on the demonstration of bioequivalence, despite strict measures are taken to control it. The objective of this study is to investigate further means of controlling IIV by optimizing study design of crossover studies.

METHODS

Data from 18 bioequivalence studies were used to develop population pharmacokinetics (popPK) models to characterize the absorption and disposition processes of 14 drugs, to estimate IOV for each drug substance and to evaluate possible correlations with biopharmaceutical properties of drug substances, classified in accordance to the Biopharmaceutics Drug Disposition Classification System (BDDCS).

RESULTS

Plasma-pharmacokinetics profiles for the 14 drugs analyzed were successfully described using popPK. The pharmacokinetic parameters that showed greater variability were first-order rate constant of absorption, duration of the zero-order absorption process, relative bioavailability and time of latency. ISCV% estimated for C_max seems to correlate with the log-Dose-Number for Class 1, 2 and 3, despite no direct correlation was observed between popPK model residual variability (RUV) and ISCV%. Nevertheless, higher RUV estimates were observed for Class 2 drugs in comparison to Class 1 and 3.

CONCLUSION

Pharmacokinetic parameters related to drug absorption showed greater variability. Ingestion of the IMP along with 240 mL of water showed to standardize gastric emptying. Given the dependency between C_max variability and dose-solubility ratio, for classes 2 and 4, ad libitum water intake may increase C_max and AUC ISCV%. A water ingestion standardization until the expected T_max of the drug is suggested.

Anaphylactic shock with pulmonary eosinophilic infiltration due to honeybee attack in a donkey: case report

ABSTRACT A case of a donkey attacked by Africanized honeybee is reported here with clinical signs of agitation, dehydration, congestion of the ocular mucous membranes, tongue edema, tachycardia and inspiratory dyspnea, and progression to death. At necropsy, diffuse, severe subcutaneous edema at face and cervical regions and severe diffuse pulmonary hyperemia with abundant edema without parenchymal collapse were observed. Microscopically, marked, diffuse deep dermis and panniculus carnosus edema and marked diffuse alveolar edema, with moderate population of eosinophils predominantly around larger caliber vessels were noted. The final diagnosis of anaphylactic shock was supported by history, clinical signs, and anatomic pathology findings. This is the first report of a honeybee attack with pulmonary eosinophilic infiltration in a mammal.

Antithrombotic strategy in patients with atrial fibrillation and acute coronary syndrome

Background

Atrial fibrillation (AF) is frequent in patients admitted with acute coronary syndromes (ACS). The development of this arrhythmia occurs in 2–21% of patients with non ST-elevation ACS and 21% of ST-elevation ACS. According with the most recent European guidelines, a short period up to 1 week of triple antithrombotic therapy (TAT) is recommended, followed by dual antithrombotic therapy (DAT) using a NOAC and a single antiplatelet agent, preferably clopidogrel.

Objective

To compare the antithrombotic strategy (DAT vs TAT) used and its prognostic value in patients with AF and ACS.

Methods

Retrospective analysis of patients' data admitted with ACS in a multicentric registry between 10/2010–09/2019. TAT was defined as the prescription of dual antiplatelet therapy and one anticoagulant and DAT as one antiplatelet and one anticoagulant. Survival and rehospitalization were evaluated through Kaplan-Meier curve.

Results

1067 patients were included, mean age 67±14 years, 72.3% male. Patients who developed de novo AF during hospitalization due to ACS were older (75±12 vs 66±14 years, p<0.001) and with higher prevalence of cardiovascular risk factors and cardiovascular disease. AF was more often in patients with ST elevation ACS (53.4%). During hospitalization, AF patients were more often medicated with aspirin, glycoprotein inhibitor, heparin, fondaparinux and vitamin K antagonists. No difference was found regarding P2Y12 inhibitors. AF patients presented more often obstructive coronary disease (normal coronaries 5.4 vs 8.5%, p<0.001) so they were more often submitted to PCI (79.5 vs 70.9%, p<0.001). AF patients presented with higher rates of adverse in-hospital events as re-infarction, heart failure, shock, ventricular arrhythmias, cardiac arrest, stroke, major bleeding and death (p<0.001). At discharge, AF patients were less prescribed with aspirin or ticagrelor, but the rate of clopidogrel prescription was higher, such as vitamin K antagonists or any of the new anticoagulants. In the AF group, 21.5% patients were discharged with TAT and 30.3% with DAT. Concerning patients discharged with TAT, 1-year follow-up revealed no significant differences in mortality (p=0.578), re-admission for cardiovascular causes (p=0.301) and total re-admission rates (p=0.291). Patients discharged with DAT had similar mortality (p=0.623) and re-admission for cardiovascular causes rates (p=0.138), but significant differences were identified regarding total re-admissions (p=0.024).

Conclusions

In patients with ACS and de novo AF, a low percentage of patients was discharged with oral anticoagulation (51.8%). In those whose anticoagulation was initiated, DAT was the preferred strategy. 1-year outcomes were not different between the antithrombotic strategy, except for all cause re-admission.

Funding Acknowledgement

Type of funding sources: None.

Treatment-induced shrinking of tumour aggregates: a nonlinear volume-filling chemotactic approach

Motivated by experimental observations in 3D/organoid cultures derived from glioblastoma, we propose a novel mechano-transduction mechanism where the introduction of a chemotherapeutic treatment induces mechanical changes at the cell level. We analyse the influence of these individual mechanical changes on the properties of the aggregates obtained at the population level. We employ a nonlinear volume-filling chemotactic system of partial differential equations, where the elastic properties of the cells are taken into account through the so-called squeezing probability, which depends on the concentration of the treatment in the extracellular microenvironment. We explore two scenarios for the effect of the treatment: first, we suppose that the treatment acts only on the mechanical properties of the cells and, in the second one, we assume it also prevents cell proliferation. We perform a linear stability analysis which enables us to identify the ability of the system to create patterns and fully characterize their size. Moreover, we provide numerical simulations in 1D and 2D that illustrate the shrinking of the aggregates due to the presence of the treatment.

Bernard Soulier syndrome: a rare, frequently misdiagnosed and poorly managed bleeding disorder

Bernard Soulier syndrome is a rare, congenital platelet bleeding disorder, with autosomal recessive inheritance. It is characterised by macrothrombocytopenia and platelet dysfunction, leading to mucocutaneous bleeding noted in early childhood. This entity poses an important diagnostic challenge, and blood smear and DNA sequencing are paramount for the correct diagnosis. Differential diagnosis includes May-Hegglin anomaly, Glanzmann Thrombasthenia and von Willebrand disease; it is also often misdiagnosed as idiopathic thrombocytopenic purpura. We report a 68-year-old man diagnosed with von Willebrand disease for three decades, admitted with gastrointestinal bleeding, anaemia and severe thrombocytopenia. Replacement with von Willebrand factor did not stop the haemorrhage, suggesting another aetiology for the bleeding disorder. Corticosteroids and intravenous immune globulin were also ineffective. Genetic sequencing showed a homozygous mutation in GP1BA gene, thus establishing the correct diagnosis.

Sustained ventricular tachycardia as a predictor of major adverse cardiac events in acute coronary syndrome patients

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Portuguese Registry of Acute Coronary Syndromes

Background

Sustained ventricular tachycardia (VT) is a frequent rhythm disturbance during an ischemic event like acute coronary syndrome (ACS). VT was frequently associated with worse prognosis, then is expected, that its presence is related to a higher incidence of major adverse cardiac events (MACE).

Objective

Evaluate if sustained VT was a predictor of MACE in ACS hospitalized patients.

Methods

Multicenter retrospective study, based on the Portuguese Registry of ACS between 1/10/2010-4/09/2019. Patients were divided into two groups: A – patients without VT, and B – patients that presented VT on the hospitalization. VT was defined as a register or more of the VT with at least 30 seconds. Were excluded patients without a previous cardiovascular history or clinical data. MACE was defined as re-infarction, congestive heart failure, cardiogenic shock, a mechanical complication of myocardial infarction, completed atrioventricular block, sustained ventricular tachycardia, cardiac arrest, stroke and hospitalization death. Univariate logistic regression was performed to assess if VT in ACS patients was a predictor of MACE.

Results

A total of 29851 patients was analyze and 25725 had information regarding VT. From the group of patients that presented VT, 177 (1.1%) had re-infarction, 2415 (14.1%) had congestive heart failure, 816 (5.0%) had atrial fibrillation, 108 (0.7%) had a mechanical complication of myocardial infarction, 442 (2.7%) had completed atrioventricular block, 458 (2.8%) had cardiac arrest, 101 (0.6%) had stroke and 535 (3.3%) died. VT did not predict re-infarction (p = 0.071), mechanical complication of myocardial infarction (p = 0.979) and stroke (p = 0.500) in ACS hospitalized patients. Logistic regression revealed that VT in ACS patients was a predictor of congestive heart failure (odds ratio (OR) 2.304, p < 0.001, confidence interval (CI) 1.742-3.047), atrial fibrillation (OR 2.078, p < 0.001, CI 1.453-2.973), completed atrioventricular block (OR 1.831, p = 0.012, CI 1.145-2.928), cardiac arrest (OR 15.434, p < 0.001, CI 11.429-20.843) and hospitalization death (OR 6.472, p < 0.001, CI 4.484-9.342).

Conclusions

VT in ACS patients predict MACE, namely congestive heart failure, atrial fibrillation, completed atrioventricular block, cardiac rest and hospitalization death.

Was the atrioventricular block similar in anterior and inferior ST-elevation myocardial infarction?

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Portuguese Registry of Acute Coronary Syndromes

Background

The presence of atrioventricular block (AVB) in ST-elevation myocardial infarction (STEMI) is more frequently registered when is identified in the inferior leads. However, AVB maybe occurs in anterior STEMI, yet the AVB and STEMI localization maybe had different implications.

Objective

Evaluate the impact and prognosis of AVB according to the STEMI localization.

Methods

Multicenter retrospective study, based on the Portuguese Registry of Acute Coronary Syndrome between 1/10/2010-3/05/2020. Patients were divided into two groups: A – patients with anterior STEMI, and B – patients with inferior STEMI. Were excluded patients without a previous cardiovascular history or clinical data regarding AVB occurrence. Logistic regression was performed to assess AVB as a prognostic marker in STEMI patients.

Results

From 32157 patients, was identified 462 with AVB, 72 in group A (15.6%) and 390 in group B (84.4%). Both groups were similar regarding gender (p = 0.710), age (p = 0.068), body mass index (p = 0.535), admitly directly to cat lab (p = 0.635), initial symptons until first medical contact (p = 0.561), smoker status (p = 0.483), diabetes mellitus (p = 0.331), coronary artery disease (p = 0.053), previous stroke (p = 0.332),  peripheral artery disease (p = 0.348), chronic kidney disease (p = 0.425), systolic blood pressure (p = 0.057), multivessel diasease (p = 0.235), new-onset of atrial fibrillation (p = 0.582), cardiac arrest (p = 0.062) and stroke complication (p = 0.685). Group B had higher left ventricular ejection fraction (LVEF) >50% (16.9 vs 60.7%, p < 0.001). On the other hand, group A had more arterial hypertension (79.7 vs 66.2%, p = 0.027), dislipidaemia (58.2 vs 54.4%, p = 0.038), heart rate at admission (81 ± 20 vs 59 ± 23, p < 0.001), Killip-Kimball class > I (45.7 vs 29.6%, p = 0.008), sinus rhythm at admission (84.5 vs 72.6%, p = 0.035), heart failure complication (65.3 vs 37.1%, p < 0.001), cardiogenic shock complication (42.3 vs 24.7%, p < 0.001), ACS mechanical complication (8.3 vs 3.1%, p = 0.047), sustained ventricular tachycardia during ACS hospitalization (19.4 vs 8.5%, p = 0.005) and hospitalization death (52.9 vs 44.7%, p < 0.001). Logistic regression revealed that AVB in inferior STEMI was a predictor of new-onset of atrial fibrillation (odds ratio (OR) 3.817, p = 0.038, confidence interval (CI) 1.123-12.975), with a R2 Nagelkerke 24.4. Also, revealed that AVB in anterior STEMI was a predictor of death (OR 0.111, p < 0.001, CI 0.034-0.366), with a R2 Nagelkerke 55.2.

Conclusions

AVB in inferior STEMI was a predictor of new-onset of atrial fibrillation and AVB in anterior STEMI was a predictor of death.

Sustained ventricular tachycardia in acute coronary syndromes the Portuguese experience

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Portuguese Registry of Acute Coronary Syndromes

Background

Acute coronary syndromes (ACS) are frequent and are associated with high levels of comorbidities and complications. Ventricular tachycardia (VT) is one of the most danger and stressful situations in ACS.

Objective

Evaluate predictors of ventricular tachycardia in ACS.

Methods

Multicenter retrospective study, based on the Portuguese Registry of ACS between 1/10/2010-4/09/2019. Patients were divided in two groups: A – patients without VT, and B – patients that presented VT on the hospitalization. VT was defined as a register or more of the VT with at least 30 seconds. Logistic regression was performed to assess predictors of VT in ACS patients.

Results

25361 in group A (98.6%) and 364 in group B (1.4%). Both groups were similar regarding gender, cardiovascular risk factors, except for dyslipidemia (61.7 vs 51.9%, p < 0.001) and ST-segment elevation myocardial infarction (STEMI) location. Group B was elderly (67 ± 14 vs 70 ± 14, p < 0.001), was admitted directly to the cat lab (10.6 vs 20.4%, p < 0.001), had less time since the onset of symptoms until the admission (383 ± 157 vs 349 ± 121, p = 0.003), but presented higher previous history of heart failure (5.9 vs 10.6%, p < 0.001), peripheral vascular disease (5.5 vs 8.4%, p = 0.015), chronic obstructive pulmonary disease (COPD) (4.4 vs 7.9%, p = 0.001) and dementia (1.7 vs 3.2%, p = 0.038). At admission presented higher levels of STEMI (42 vs 67%, p < 0.001), dyspnea (29 vs 18.1%, p < 0.001), syncope (1.3 vs 6.6%, p < 0.001), cardiac arrest (0.4 vs 4.4%, p < 0.001), Killip-Kimball classification > I (14.8 vs 40.5%, p < 0.001) and atrial fibrillation at admission (AF) (7.1 vs 15.3%, p < 0.001). Ivabradine (3.7 vs 7.6%, p < 0.001), aldosterone receptor antagonists (10.2 vs 24%, p < 0.001), diuretic (28 vs 57.2%, p < 0.001), amiodarone (5.6 vs 53.5%, p < 0.001), digoxin (1.4 vs 4.7%, p < 0.001) were more prevalent used in the admission. Group B exhibited higher multivessel disease (MVD) (51.5 vs 61.5%, p < 0.001), culprit as common coronary trunk (CT) (1.7 vs 4.2%, p = 0.024), hybrid revascularization (0.8 vs 2%, p = 0.032) and left ventricular ejection fraction (LVEF)<50% (38.7 vs 71%, p < 0.001). On the other hand, the used of beta block (81.4 vs 62.3%, p < 0.001), angiotensin-converting-enzyme inhibitor (85.5 vs 74.4%, p < 0.001) and calcium channel blockers (10.1 vs 24%, p < 0.001) since had a protect effect. Regarding reinfarction (0.9 vs 2.5%, p = 0.007), de novo heart failure (15.1 vs 50.3%, p < 0.001), atrioventricular block (2.2 vs 17%, p < 0.001), stroke (1.4 vs 4.9%, p < 0.001) and death (3.4 vs 26.9%, p < 0.001), all were higher in Group B. Logistic regression revealed COPD (odds ratio (OR) 1.9, p = 0.010, confidence interval (CI) 1.17-3.10), STEMI (OR 2.73, p < 0.001, CI 2.00-3.73), AF (OR 2.30, p < 0.001, CI 1.52-3.49), MVD (OR 1.44, p = 0.012, CI 1.08-1.92), CT (OR 2.87, p = 0.003, CI 1.45-5.69) and LVEF < 50%  (OR 3.44, p < 0.001, CI 2.52-4.71) as predictors of VT in ACS.

Conclusions

COPD, STEMI, AF, MVD, CT and LVEF < 50% were predictors of VT in ACS.

Endocardial left ventricular pacing Where are we a systematic review

Funding Acknowledgements

Type of funding sources: None.

Background

Endocardial left ventricular pacing is a technique used in cardiac resynchronization therapy (CRT), when a coronary sinus implant is not possible, conventional CRT was an unsuccess and in CRT nonresponders. We performed a systemic review to evaluate its risks and benefits.

Objective

Review the evidence regarding the efficacy and safety of endocardial left ventricular pacing.

Methods

A systemic research on MEDLINE and PUBMED with the term "endocardial left ventricular pacing", "biventricular pacing" or "endocardial left pacing". 1038 results were identified, however, just publish papers (excluding abstract) with more than 16 patients was admitted in these analyses. Comparisons pre and post CRT regard New York Heart Association (NYHA) functional classification, left ventricular ejection fraction (LVEF) and QRS width was performed. Mean differences (MD) and confidence interval (CI) was used as a measurement of treatment.

Results

Eleven studies were selected, including a total of 560 patients. The studies were performed with different techniques, trans-atrial septal technique, trans-ventricular septal technique and transapical technique. Mean age 66.93 years old, 90.54% male, median ejection fraction of 28.86%, NYHA class of 3.03, QRS width 167,50 mseg. Ischemic etiologic in 43.88%, atrial fibrillation in 45.35% and left bundle branch block in 55.20%. Was reported several complications after the procedure, 8 pocket infection (7 studies), 17 transient ischemic attacks (10 papers), 17 ischemic stroke (all), 35 tromboembolic events (all) and 115 deaths, nevertheless, follow up in the different studies was diverse and heterogeneous. Significant improvement was registered in NYHA class (MD 0.64, CI 0.56-0.72, p < 0.00001, I2 = 89%) (reported in 7 studies), LVEF (MD 6.20, CI 5.09-7.32, p = 0.002, I2 = 69%) %) (reported in 8 studies) and QRS width (MD 31.35, CI 26.11-36.60, p < 0.00001, I2 = 89%) %) (reported in 5 studies), (all p < 0.00001).

Conclusions

Left ventricular endocardial pacing is a feasible alternative to conventional CRT, when the last one is not possible. With clinical, electrocardiogram and echocardiogram improvement in several series. First data regarding this procedure were associated with higher stroke incidence, something contrary to the last study’s results. Nevertheless, at the moment just small series present this technique with heterogenous results and different approaches, being important further investigation.

Septal vs apical defibrillator electrode placement a systematic review

Funding Acknowledgements

Type of funding sources: None.

Background

The optimal right ventricular defibrillator lead placement is still a debatable matter. We attempt to performed a systemic review to evaluate whether septal and apical placement had significant differences in the follow-up with an indication for implantation of these devices.

Objective

Review the evidence regarding the efficacy and safety of right ventricular apical and septal defibrillator lead placement.

Methods

A systemic research on MEDLINE and PUBMED with the term "septal pacing", "apical pacing" "septal defibrillation" or "apical defibrillation". 309 results were identified, however, after a serious analysis, several articles were excluded. Comparisons between apical and septal placement were performed regarding R wave amplitude, pacing threshold at 0.5 ms, lead impedance, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD) and lead complication that produced lead re-placement. Mean differences (MD) and confidence interval (CI) was used as a measurement of treatment.

Results

Six studies were selected, including a total of 2180 patients. The studies were performed with different techniques, analyses and goals. The studies presented heterogeneous and diverse results, with a varied follow-up period, that resulted in the exclusion of one of the studies. Mean age 64.51 years old, 76.86% male, a median ejection fraction of 27.84%, NYHA class of 2.65, ischemic etiologic in 51.10% and a follow-up period of 26.49 months. Septal defibrillator lead placement was established in 772 patients, while the apical defibrillator lead placement was performed in 1399 patients. No differences regarding the lead performance on apical and septal placement were detected regarding the R-wave (MD -0.36, CI -0.75 - +0.03, p = 0.68, I2 = 0%) (reported in 3 studies) and lead impedance (MD -23.83, CI -51.36 - +3.69, p = 0.003, I2 = 82%) (reported in 3 studies). Pacing threshold seems to be favor a septal defibrillator lead implantation (MD -0.05, CI -0.09 - -0.02, p = 0.12, I2 = 53%) (reported in 3 studies). Concerning echocardiography parameters during the follow up period, LVEF (MD -0.83, CI -3.05 - +1.38, p = 0.10, I2 = 57%) (reported in 3 studies) and LVEDD (MD -0.51, CI -2.13 - +1.10, p = 0.20, I2 = 38%) (reported in 3 studies) were not significant influenced for the defibrillator lead placement. Lead complications that provoke a lead replacement was not significant between the lead placement (MD 1.25, CI 0.53 – 2.94, p = 0.71, I2 = 0%) (reported in 3 studies).

Conclusions

Just pacing threshold proved to improve the septal defibrillator lead placement. Neither the other lead parameters or the echocardiography results during the follow-up were influenced by the lead placement. For a definitive conclusion is important to further investigation.

Prognosis of new-onset of atrial fibrillation in acute coronary syndrome: Portuguese experience

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Portuguese Registry of Acute Coronary Syndromes

Background

Acute coronary syndrome (ACS) and atrial fibrillation (AF) are common diseases in developed countries and in some cases, the first episode of AF can occur during the ACS. A stressful event like an ACS can be a trigger for AF, being important to realize its impact and prognosis in the short and long term.

Objective

Evaluate the impact and prognosis of new-onset AF in ACS.

Methods

Multicenter retrospective study, based on the Portuguese Registry of ACS between 1/10/2010-4/09/2019. Patients were divided into two groups: A – patients without new-onset AF, and B – patients that presented new onset of AF. Were excluded patients without a previous cardiovascular history or clinical data during the admission and the follow-up period. Logistic regression was performed to assess if new-onset AF in ACS was a predictor of major adverse cardiac events and mortality. Kaplan-Meier test was performed to establish the survival rates and re-admission for one year of follow up.

Results

9687 patients suffered ACS and had follow-up at 1 year, 9264 in group A (95.6%) and 423 in group B (4.4%). Both groups were similar regarding dyslipidemia, diabetes mellitus, previous coronary artery disease, multivessel disease after the cardiac catheterization. Group A had more smokers (28.2 vs 17.8%, p < 0.001) and left ventricular ejection fraction (LVEF) >50% (69.2 vs 45.1%, p < 0.001). On the other hand, group B was elderly (67 ± 14 vs 75 ± 12, p < 0.001), female (26.9 vs 34.0%, p < 0.001), arterial hypertension (70.5 vs 77.5%, p = 0.005), was more admitted directly to the cat lab (12.5 vs 17.7%, p = 0.002), ST-segment elevation myocardial infarction (40.2 vs 49.9%, p < 0.001), Killip-Kimball classification > I (12.8 vs 34.8%, p < 0.001) and hybrid revascularization (0.7 vs 2.4%, p = 0.002). Logistic regression revealed that new-onset of AF in ACS patients was a predictor of congestive heart failure (odds ratio (OR) 1.75, p < 0.001, confidence interval (CI) 1.47-2.09), cardiogenic shock (OR 3.08, p < 0.001, CI 2.37-4.01), sustained ventricular tachycardia (OR 2.29, p < 0.001, CI 1.61-3.25) and intrahospital mortality (OR 1.99, p < 0.001, CI 1.51-2.63). Nevertheless, new-onset of AF was not associated with re-infarction (p = 0.361), mechanical complications (p = 0.319), atrioventricular block (p = 0.574), stroke (p = 0.131) and cardiac arrest (p = 0.060) during the hospitalization for ACS. Mortality rates at one year of follow-up showed significant differences, p < 0.001, between the two groups (Figure 1). Similar results were found concerning re-admission for all causes, p = 0.021 (Figure 2), on the other causes, re-admission for cardiovascular causes do not reveal to be significant, p = 0.515.

Conclusions

New-onset of AF in ACS was a predictor of congestive heart failure, cardiogenic shock, sustained ventricular tachycardia and intrahospital mortality. AF was associated with higher mortality rates and re-admission for all causes at one year follow up.

Atrioventricular block in acute coronary syndrome: Portuguese experience

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Portuguese Registry of Acute Coronary Syndromes

Background

The atrioventricular block (AVB) occurrence in acute coronary syndrome (ACS) is a potentially life-threatening complication, that demand a rapid and efficient response regarding reperfusion time and rhythm stabilization.

Objective

Evaluate the impact and prognosis of AVB in ACS patients, as well as predictors of AVB.

Methods

Multicenter retrospective study, based on the Portuguese Registry of ACS between 1/10/2010-3/05/2020. Patients were divided into two groups: A – patients without AVB, and B – patients that presented AVB. Were excluded patients without a previous cardiovascular history or clinical data regarding AVB occurrence. Logistic regression was performed to assess predictors of AVB in ACS patients.

Results

From 32157 patients, 23774 was included, 23148 in group A (97.4%) and 626 in group B (2.6%). Both groups were similar regarding initial symptons until first medical contact (p = 0.410), smoker status (p = 0.222), arterial hypertension (p = 0.776), diabetes mellitus (p = 0.508), peripheral artery disease (p = 0.479), chronic kidney disease (p = 0.467) and re-infarction during the hospitalization for ACS (p = 0.145). Group A had higher body mass index (27.4 ± 4.4 vs 26.9 ± 4.6, p = 0.005), dislipidaemia (59.6 vs 51.4%, p < 0.001), coronary artery disease (18.9 vs 13.0, p < 0.001), heart rate (78 ± 19 vs 65 ± 25, p < 0.001), systolic blood pressure (139 ± 29 vs 119 ± 32, p < 0.001) and left ventricular ejection fraction (LVEF) >50% (60.1 vs 51.7%, p < 0.001). On the other hand, group B was elderly (66 ± 13 vs 71 ± 13, p < 0.001), female (27.4 vs 32.4%, p < 0.001), previous stroke (6.9 vs 10.9%, p < 0.001), neoplasia (4.9 vs 6.8%, p = 0.031), ST-segment elevation myocardial infarction (46.2 vs 75.4%, p < 0.001), syncope as major symptom (1.3 vs 10.0%, p < 0.001), Killip-Kimball class > I (15.4 vs 31.6%, p < 0.001), multivessel diasease (52.1 vs 61.4%, p < 0.001), heart failure complication (15.5 vs 40.6%, p < 0.001), cardiogenic shock complication (3.8 vs 24.6%, p < 0.001), new-onset of atrial fibrillation (4.2 vs 14.1%, p < 0.001), ACS mechanical complication (0.6 vs 3.2%, p < 0.001), sustained ventricular tachycardia during ACS hospitalization (1.3 vs 10.0%, p < 0.001), cardiac arrest (2.7 vs 13.3%, p < 0.001), stroke complication (0.6 vs 1.9%, p < 0.001) and hospitalization death (3.5 vs 19.0%, p < 0.001). Logistic regression revealed that female gender (odds ratio (OR) 1.422, p = 0.015, confidence interval (CI) 1.072-1.885), age ≥75 years old (OR 1.560, p = 0.002, CI 1.174-2.073), heart rate <60 (OR 6.692, p < 0.001, CI 5.180-8.644) and Killip-Kimball class > I (OR 3.264, p < 0.001, CI 2.446-5.356) were predictors of AVB in ACS patients.

Conclusions

Female gender, age ≥75 years old, heart rate <60 and Killip-Kimball class > I were predictors of AVB in ACS patients.

Cardiovascular risk factors as predictors of new onset atrial fibrillation during hospitalization for Acute Coronary Syndromes

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Portuguese Registry of Acute Coronary Syndromes

Background

Cardiovascular risk factors (CVRF) are a growing health problem in developed countries, being directly associated with acute coronary syndrome (ACS) occurrence and atrial fibrillation (AF). Nevertheless, new onset of AF in context of ACS is a clinical problem with prognostic and therapeutic implications.

Objective

Evaluate the impact of the CVRF in new onset AF during the hospitalization for ACS.

Methods

Multicenter retrospective study, based on the Portuguese Registry of ACS between 1/10/2010-4/09/2019. Patients were divided in two groups: A – without new onset of AF during the hospitalization for ACS and B – with new onset of AF during the hospitalization for ACS. CVFR was defined by body mass index, diabetes, arterial hypertension, smoking, coronary artery disease, neoplasia, dyslipidemia, chronic kidney disease and peripheral arterial disease. Logistic regression was performed to assess predictors of new onset AF in these patients.

Results

14037 patients were included, 637 in group B (4.8%). Both groups were similar regarding diabetes mellitus (p = 0.116), coronary artery disease (p = 0.264) and neoplasia (p = 0.327). Curiously the group A exhibited higher body mass index (27.5 ± 4.3 vs 27.2 ± 4.4, p < 0.001), smokers (28.1 vs 18.5%, p < 0.001) and dyslipidemia (62.8 vs 56.7%, p < 0.001). On the other hand, group B presented more females (26.4 vs 35.0%, p < 0.001), arterial hypertension (70.0 vs 74.9%, p = 0.002), peripheral arterial disease (5.4 vs 8.4%, p < 0.001) and chronic kidney disease (6.7 vs 9.5%, p < 0.001). Logistic regression revealed that body mass index, smoker status, diabetes, dyslipidemia, coronary artery disease, neoplasia, chronic kidney disease and peripheral arterial disease were not predictors of AF during the hospitalization for ACS. Nonetheless, female gender (odds ratio (OR) 1.23, p = 0.025, confidence interval (CI) 1.03-1.47), obesity (OR 1.39, p = 0.004, CI 1.11-1.74) and arterial hypertension (OR 1.22, p = 0.049, CI 1.01-1.50) were predictors of new onset of AF during hospitalization for ACS. Conclusions: Female gender, obesity and arterial hypertension were predictors of new onset of AF in during hospitalization for ACS.

Cardiovascular risk factors as predictors of heart failure during hospitalization for Acute Coronary Syndromes

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Portuguese Registry of Acute Coronary Syndromes

Background

Cardiovascular risk factors (CVRF) are a growing health problem in developed countries. These patients have a higher prevalence of acute coronary syndromes (ACS) and as a consequence ACS complication, like heart failure (HF). HF after an ACS is a common complication and CVFR can influence its manifestation.

Objective

Evaluate the impact of the CVRF in HF during the hospitalization for ACS.

Methods

Multicenter retrospective study, based on the Portuguese Registry of ACS between 1/10/2010-4/09/2019. Patients were divided in two groups: A – without new onset of HF during the hospitalization for ACS and B – with new onset of HF during the hospitalization for ACS. CVFR was defined by body mass index, diabetes, arterial hypertension, smoking, neoplasia, dyslipidemia, coronary artery disease, chronic kidney disease and peripheral arterial disease. Logistic regression was performed to assess predictors of new onset HF in these patients.

Results

14717 patients were included, 2287 in group B (15.5%). Both groups were similar regarding body mass index (27.5 ± 4.3 vs 27.2 ± 4.4, p = 0.254). Curiously the group A exhibited higher prevalence of smoking status (29.8 vs 16.6%, p < 0.001). On the other hand, group B presented more females (25.0 vs 35.7%, p < 0.001), arterial hypertension (68.7 vs 78.2%, p < 0.001), diabetes mellitus (28.5 vs 43.1%, p < 0.001), dyslipidemia (62.2 vs 64.3%, p = 0.023), coronary artery disease (19.6 vs 25.6%, p < 0.001), neoplasia (4.4 vs 7.0%, p < 0.001), peripheral arterial disease (5.2 vs 15.8%, p < 0.001) and chronic kidney disease (4.6 vs 10.0%, p < 0.001). Logistic regression revealed that body mass index, diabetes, arterial hypertension, neoplasia and dyslipidemia were not predictors of HF during the hospitalization for ACS. Nevertheless, female gender (odds ratio (OR) 1.37, p < 0.001, confidence interval (CI) 1.22-1.54), chronic kidney disease (OR 1.59, p < 0.001, CI 1.33-1.90) and peripheral arterial disease (OR 1.54, p < 0.001, CI 1.27-1.86) were predictors of new onset of HF during hospitalization for ACS. Curiously, smoking seems to have a protective effect (OR 0.68, p < 0.001, CI 0.59-0.78) in new onset HF in ACS patients.

Conclusions

Chronic kidney disease and peripheral arterial disease were predictors of new onset of HF in during hospitalization for ACS.

Acute Coronary Syndrome follow up: Portuguese experience

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Portuguese Registry of Acute Coronary Syndromes

Background

Acute coronary syndrome is a major health problem, with several acute and chronic complications. So, it is imperative identifying factors that can be associated with better and worse prognosis during the follow up these patients.

Objective

Evaluate predictors of mortality, cardiovascular readmission and all causes of readmission at 1 year follow up in ACS patients.

Methods

Multicenter retrospective study, based on the Portuguese Registry of ACS between 1/10/2010-4/09/2019. Logistic regression was performed to assess predictors of mortality, cardiovascular readmission and all causes of readmission at 1 year follow up in ACS patients.

Results

1492 patients were included, 141 die during the first year. Age > 75 years old (odds ratio (OR) 2.557, p < 0.001, confidence interval (CI) 1.727-3.785), heart rate < 60 (OR 2.686, p = 0.008, CI 1.296-5.569), cardiogenic shock (OR 6.726, p = 0.012, CI 1.512-29.915), creatinine >2mg/dL (OR 1.956, p = 0.023, CI 1.099-3.480), left ventricular ejection fraction <50% (OR 1.911, p = 0.001, CI 1.284-2.844), nitrate (OR 1.589, p = 0.020, CI 1.074-2.351), ivabradine (OR 1.831, p = 0.011, CI 1.146-2.924), aldosterone antagonists (OR 1.632, p = 0.020, CI 1.079-2.468), diuretic (OR 1.625, p = 0.023, CI 1.069-2.472) and mechanical complication d (OR 55.518, p < 0.001, CI 11.516-267.655) were predictors of mortality of 1 year of follow up. Regarding cardiovascular readmission was registered in 291 patients, of a total 1412. Were predictors of cardiovascular readmission previous history of heart failure (OR 1.467, p = 0.003, CI 1.135-1.895), cardiogenic shock (OR 3.447, p = 0.039, CI 1.068-11.128), acetylsalicylic acid previous to ACS (OR 1.751, p = 0.008, CI 1.285-2.385), multivessel disease (OR 1.667, p = 0.002, CI 1.206-2.306), left ventricular ejection fraction <50% (OR 1.489, p = 0.003, CI 1.145-1.938), nitrate (OR 1.812, p < 0.001, CI 1.403-2.341), aldosterone antagonists (OR 1.572, p = 0.004, CI 1.155-2.140) and sustained ventricular tachycardia (OR 55.518, p < 0.001, CI 11.516-267.655). On the other hand 411 patients was readmitted (all causes), in 1455 patients with follow up. Were predictors of all causes of readmission previous history of heart failure (OR 1.347, p = 0.025, CI 1.039-1.747), previous chronic obstructive pulmonary disease (OR 1.456, p = 0.041, CI 1.016-2.087), atrial fibrillation (OR 1.439, p = 0.027, CI 1.041-1.988), acetylsalicylic acid previous to ACS (OR 1.473, p = 0.001, CI 1.161-1.869), left ventricular ejection fraction <50% (OR 1.456, p = 0.001, CI 1.166-1.819), nitrate (OR 1.478, p < 0.001, CI 1.192-1.831), aldosterone antagonists (OR 1.493, p = 0.003, CI 1.148-1.943) and sustained ventricular tachycardia (OR 3.792, p = 0.004, CI 1.540-9.337). Conclusions: Left ventricular ejection fraction <50%, nitrate as discharge therapeutic and aldosterone antagonists as discharge therapeutic were predictors of mortality, cardiovascular readmission and readmission for all causes at 1 year follow up.

Cardiovascular risk factors as predictors of completed atrioventricular block during hospitalization for Acute Coronary Syndromes

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Portuguese Registry of Acute Coronary Syndromes

Background

The presence of cardiovascular risk factors (CVRF) are directly related to acute coronary syndrome (ACS) occurrence. ACS is a major health problem with multiple complications. Completed atrioventricular block (CAVB) in context of ACS can impact the patient’s prognosis, and is not clarified if its presence can be predicted only by CVFR.

Objective

Evaluate the impact of the CVRF in CAVB during the hospitalization for ACS.

Methods

Multicenter retrospective study, based on the Portuguese Registry of ACS between 1/10/2010-4/09/2019. Patients were divided in two groups: A – without CAVB during the hospitalization for ACS and B – with CAVB during the hospitalization for ACS. CVFR was defined by body mass index, diabetes, arterial hypertension, smoking, coronary artery disease, neoplasia, dyslipidemia, chronic kidney disease and peripheral arterial disease. Logistic regression was performed to assess predictors of CAVB in these patients.

Results

14031 patients were included, 401 in group B (2.9%). Both groups were similar regarding smoking status (p = 0.920), arterial hypertension (p = 0.928), diabetes mellitus (p = 0.249), peripheral arterial disease (p = 0.352) and chronic kidney disease (p = 0.783). Interestingly the group A exhibited higher body mass index (27.4 ± 4.3 vs 26.9 ± 4.5, p < 0.001), dyslipidemia (62.8 vs 53.6%, p < 0.001) and coronary artery disease (20.7 vs 15.0%, p = 0.001). On the other hand, group B presented more females (26.7 vs 31.5%, p = 0.012), mean age (66 ± 13 vs 71 ± 13, p < 0.001) and neoplasia (4.8 vs 7.1%, p = 0.012). Logistic regression revealed that any of the CVRF were a predictor of CAVB during the hospitalization for ACS. Just, age (odds ratio 1.48, p < 0.001, confidence interval 1.16-1.88) has been a predictor of CAVB during hospitalization for ACS.

Conclusions

Any CVFR was a predictor of CAVB in context of ACS. Age was a predictor of CAVB during hospitalization for ACS.

Clarithromycin impairs tissue-resident memory and Th17 responses to macrolide-resistant Streptococcus pneumoniae infections

Abstract

The increasing prevalence of antimicrobial resistance in pathogens is a growing public health concern, with the potential to compromise the success of infectious disease treatments in the future. Particularly, the number of infections by macrolide antibiotics-resistant Streptococcus pneumoniae is increasing. We show here that Clarithromycin impairs both the frequencies and number of interleukin (IL)-17 producing T helper (Th) 17 cells within the lungs of mice infected with a macrolide-resistant S. pneumoniae serotype 15A strain. Subsequently, the tissue-resident memory CD4⁺ T cell (Trm) response to a consecutive S. pneumoniae infection was impaired. The number of lung resident IL-17⁺ CD69⁺ Trm was diminished upon Clarithromycin treatment during reinfection. Mechanistically, Clarithromycin attenuated phosphorylation of the p90-S6-kinase as part of the ERK pathway in Th17 cells. Moreover, a strong increase in the mitochondrial-mediated maximal respiratory capacity was observed, while mitochondrial protein translation and mTOR sisgnaling were unimpaired. Therefore, treatment with macrolide antibiotics may favor the spread of antimicrobial-resistant pathogens not only by applying a selection pressure but also by decreasing the natural T cell immune response. Clinical administration of macrolide antibiotics as standard therapy procedure during initial hospitalization should be reconsidered accordingly and possibly be withheld until microbial resistance is determined.

Key messages

• Macrolide-resistant S. pneumoniae infection undergoes immunomodulation by Clarithromycin

• Clarithromycin treatment hinders Th17 and tissue-resident memory responses

• Macrolide antibiotics impair Th17 differentiation in vitro by ERK-pathway inhibition

Supplementary Information

The online version contains supplementary material available at 10.1007/s00109-021-02039-5.

Racial differences in mammographic density in Brazil: implications for mammographic screening

Background

Mammographic density (MD)-the amount of radio-dense fibroglandular tissue seen on a mammogram - is a stronger biomarker of susceptibility to breast cancer and a major determinant of the sensitivity of mammographic screening. This study examined for the first time racial differences in MD in Brazil.

Methods

555 women (215 from the Longitudinal Study of Adult Health - ELSA-Brasil and 340 users of the Unified Health System - SUS) in Bahia were enrolled into the study. Participants completed an interview, had their heights and weights measured, and underwent a 2-view (cranio-caudal (CC) and medio-lateral-oblique (MLO)) digital mammography of each breast. MD was measured on the left MLO image using the semi-automated Cumulus software, and expressed as the percentage (PMD) of the breast area occupied by fibroglandular tissue. Linear regression models were fitted to assess ethnicity-PMD associations adjusting for age at mammography, body mass index (BMI) and reading batch (minimally-adjusted) and further for socio-economic and reproductive variables.

Results

The study population comprised 95 White (W), 270 Brown-mixed (Bm) and 169 Black (B) women, with a mean age at mammography of 58 (SD = 5.4) years. 63% W, 69% Bm and 49% B women had low educational level; 24% W, 47% Bm and 31% B women had ≥4 children. Minimally-adjusted analysis showed that relative to W women, PMD was 23% (1.23; 95% CI 1.04-1.45) higher in Bm and 4% (1.04; 0.89-1.21) higher in B; however, further adjustment for socio-economic and reproductive variables attenuated the racial differences (fully-adjusted model: 16% (1.16; 0.96-1.40) and 9% (1.09; 0.92-1.29) for Bm and B, respectively.

Conclusions

The racial differences in PMD were mainly accounted by ethnic differences in socio-economic and reproductive-related factors.

Implications Further studies should examine whether racial differences in PMD in Brazil lead to racial differences in false negative and interval cancer rates of mammographic screening.

Key messages

In Brazil, ethnic differences in socio-economic and reproductive-related factors are responsible for racial differences in mammographic density. More research is needed to address racial differences in breast cancer risk in Brazil.

Neuroimaging Advances in Deep Brain Stimulation: Review of Indications, Anatomy, and Brain Connectomics

Deep brain stimulation is an established therapy for multiple brain disorders, with rapidly expanding potential indications. Neuroimaging has advanced the field of deep brain stimulation through improvements in delineation of anatomy, and, more recently, application of brain connectomics. Older lesion-derived, localizationist theories of these conditions have evolved to newer, network-based "circuitopathies," aided by the ability to directly assess these brain circuits in vivo through the use of advanced neuroimaging techniques, such as diffusion tractography and fMRI. In this review, we use a combination of ultra-high-field MR imaging and diffusion tractography to highlight relevant anatomy for the currently approved indications for deep brain stimulation in the United States: essential tremor, Parkinson disease, drug-resistant epilepsy, dystonia, and obsessive-compulsive disorder. We also review the literature regarding the use of fMRI and diffusion tractography in understanding the role of deep brain stimulation in these disorders, as well as their potential use in both surgical targeting and device programming.

Microfluidic-assisted fabrication of reverse micelle/PLGA hybrid microspheres for sustained vascular endothelial growth factor delivery

In this study, poly (d, l-lactide-co-glycolide) (PLGA) composite microspheres containing anhydrous reverse micelle (R.M.) dipalmitoylphosphatidylcholine (DPPC) nanoparticles loaded vascular endothelial growth factor (VEGF) were produced using microfluidic platforms. The VEGF-loaded R.M. nanoparticles (VRM) were achieved by initial self-assembly and subsequent lipid inversion of the DPPC vesicles. The fabricated VRMs were encapsulated into the PLGA matrix by flow-focusing geometry microfluidic platforms. The encapsulation efficiency, in vitro release profile, and the bioactivity of the produced composite microspheres were investigated. The release study showed that VEGF was slowly released from the PLGA composite microspheres over 28 days with a reduced initial burst (18  ±  4.17% in the first 24 H). The VEGF stability during encapsulation and release period was also investigated, and the results indicated that encapsulated VEGF was well preserved. Also, the bioactivity assay of the PLGA composite microspheres on human umbilical vein endothelial cells was confirmed that the encapsulated VEGF was utterly active. The present monodisperse and controllable VEGF-loaded microspheres with reproducible manner could be widely used in tissue engineering and therapeutic applications.

Functional and Structural Connectivity Patterns Associated with Clinical Outcomes in Deep Brain Stimulation of the Globus Pallidus Internus for Generalized Dystonia

BACKGROUND AND PURPOSE

Deep brain stimulation is a well-established treatment for generalized dystonia, but outcomes remain variable. Establishment of an imaging marker to guide device targeting and programming could possibly impact the efficacy of deep brain stimulation in dystonia, particularly in the absence of acute clinical markers to indicate benefit. We hypothesize that the stimulation-based functional and structural connectivity using resting-state fMRI and DTI can predict therapeutic outcomes in patients with generalized dystonia and deep brain stimulation.

MATERIALS AND METHODS

We performed a retrospective analysis of 39 patients with inherited or idiopathic-isolated generalized dystonia who underwent bilateral globus pallidus internus deep brain stimulation. After electrode localization, the volumes of tissue activated were modeled and used as seed regions for functional and structural connectivity measures using a normative data base. Resulting connectivity maps were correlated with postoperative improvement in the Unified Dystonia Rating Scale score.

RESULTS

Structural connectivity between the volumes of tissue activated and the primary sensorimotor cortex was correlated with Unified Dystonia Rating Scale improvement, while more anterior prefrontal connectivity was inversely correlated with Unified Dystonia Rating Scale improvement. Functional connectivity between the volumes of tissue activated and primary sensorimotor regions, motor thalamus, and cerebellum was most correlated with Unified Dystonia Rating Scale improvement; however, an inverse correlation with Unified Dystonia Rating Scale improvement was seen in the supplemental motor area and premotor cortex.

CONCLUSIONS

Functional and structural connectivity with multiple nodes of the motor network is associated with motor improvement in patients with generalized dystonia undergoing deep brain stimulation. Results from this study may serve as a basis for future development of clinical markers to guide deep brain stimulation targeting and programming in dystonia.

P1725 An easily dismissed suspect

Funding Acknowledgements

None

Introduction

Constrictive pericarditis (CP) is a rare etiology of heart failure. Is a chronic inflammatory process, characterized by scarring, fibrosis and pericardial calcification. Several etiologies can be associated with CP, namely infectious, idiopathy and post-surgical. In some cases, CP can extend to the myocardium and/or lead to cardiac dysfunction.

Case Report

58 years old woman, active smoking, referred to the emergency room for tachycardia on a routine electrocardiogram. History of 5 months of fatigue and dyspnea to ordinary activities, with progressive aggravation in the last month, associated with weight loss and episodic palpitations. Upon the physical examination presented jugular vein engorgement and peripheral edema. Admission electrocardiogram with atrial flutter at 150 of ventricular frequencies, without other findings. Thoracic radiography without variation (tenues pericardium enhancement), abdominal echography with moderate ascites. Blood work showed elevated liver enzymes, BNP of 230pg/ml, exclusion of infectious tuberculosis and autoimmune panel with isolated positive rheumatoid factor. Transthoracic echocardiography (TTE) at the emergency room show a non-dilated and global left ventricle hypokinesia, with reduced left ventricular ejection fraction (LVEF) and dilatation of the mitral valve ring in the genesis of moderate mitral regurgitation. Anticongestive and antiarrhythmic therapy started with rhythm conversion and clinical improve. Thoracic computed tomography scan reveals an extensive pericardial calcification. 2 months later TTE reveal a preserved LVEF, pericardial calcification, moderate mitral regurgitation, grade III diastolic dysfunction, respiration-related ventricular septal shift, increased of the mitral E-wave velocity with an E/A of 2.76, the peak mitral E-wave decreases 36% with the inspiration, dilated inferior vena cava without respiratory variation. Cardiac magnetic resonance imaging exposes a septal bounce and pericardial calcification, suggestive signs of constrictive pericarditis. The patient waits for cardiac catheterization for confirmation, being with anticoagulation, ACE inhibitors, beta-blockers and mineralocorticoid receptor antagonist medication, remaining in NYHA class I.

Discussion

Clinical suspicion of CP is key for its identification, since there is not a specific clinical manifestation and generally patients presented heart failure symptoms. Echocardiography is best tool for a clinical physician evaluate heart failure etiologies, and can be used with higher sensitivity and specificity associated to the correct criteria to the diagnosis of CP. Pericardiectomy is the standard treatment, however the moment of its performance is not well established, since patients can remain in NYHA class I several years and the surgical procedure have higher mortality rates.

Oscillatory regimes in a mosquito population model with larval feedback on egg hatching

Understanding mosquitoes life cycle is of great interest presently because of the increasing impact of vector borne diseases in several countries. There is evidence of oscillations in mosquito populations independent of seasonality, still unexplained, based on observations both in laboratories and in nature. We propose a simple mathematical model of egg hatching enhancement by larvae which produces such oscillations that conveys a possible explanation. We propose both a theoretical analysis, based on slow-fast dynamics and Hopf bifurcation, and numerical investigations in order to shed some light on the mechanisms at work in this model.

A chemotaxis-based explanation of spheroid formation in 3D cultures of breast cancer cells

Three-dimensional cultures of cells are gaining popularity as an in vitro improvement over 2D Petri dishes. In many such experiments, cells have been found to organize in aggregates. We present new results of three-dimensional in vitro cultures of breast cancer cells exhibiting patterns. Understanding their formation is of particular interest in the context of cancer since metastases have been shown to be created by cells moving in clusters. In this paper, we propose that the main mechanism which leads to the emergence of patterns is chemotaxis, i.e., oriented movement of cells towards high concentration zones of a signal emitted by the cells themselves. Studying a Keller-Segel PDE system to model chemotactical auto-organization of cells, we prove that it admits Turing unstable solutions under a time-dependent condition. This result is illustrated by two-dimensional simulations of the model showing spheroidal patterns. They are qualitatively compared to the biological results and their variability is discussed both theoretically and numerically.

Integrated Robotic and Network Simulation Method

The increasing use of mobile cooperative robots in a variety of applications also implies an increasing research effort on cooperative strategies solutions, typically involving communications and control. For such research, simulation is a powerful tool to quickly test algorithms, allowing to do more exhaustive tests before implementation in a real application. However, the transition from an initial simulation environment to a real application may imply substantial rework if early implementation results do not match the ones obtained by simulation, meaning the simulation was not accurate enough. One way to improve accuracy is to incorporate network and control strategies in the same simulation and to use a systematic procedure to assess how different techniques perform. In this paper, we propose a set of procedures called Integrated Robotic and Network Simulation Method (IRoNS Method), which guide developers in building a simulation study for cooperative robots and communication networks applications. We exemplify the use of the improved methodology in a case-study of cooperative control comparison with and without message losses. This case is simulated with the OMNET++/INET framework, using a group of robots in a rendezvous task with topology control. The methodology led to more realistic simulations while improving the results presentation and analysis.

Mosquito population control strategies for fighting against arboviruses

In the fight against vector-borne arboviruses, an important strategy of control of epidemic consists in controlling the population of the vector, Aedes mosquitoes in this case. Among possible actions, two techniques consist either in releasing sterile mosquitoes to reduce the size of the population (Sterile Insect Technique) or in replacing the wild population by one carrying a bacteria, called Wolbachia, blocking the transmission of viruses from insects to humans. This article addresses the issue of optimizing the dissemination protocol for each of these strategies, in order to get as close as possible to these objectives. Starting from a mathematical model describing population dynamics, we study the control problem and introduce the cost function standing for population replacement and sterile insect technique. Then, we establish some properties of the optimal control and illustrate them with numerical simulations.

Obesity paradox in cancer: Is bigger really better?

While obesity is widely recognized as a risk factor for cancer, survival among patients with cancer is often higher for obese than for lean individuals. Several hypotheses have been proposed to explain this "obesity paradox," but no consensus has yet emerged. Here, we propose a novel hypothesis to add to this emerging debate which suggests that lean healthy persons present conditions unfavorable to malignant transformation, due to powerful natural defenses, whereby only rare but aggressive neoplasms can emerge and develop. In contrast, obese persons present more favorable conditions for malignant transformation, because of several weight-associated factors and less efficient natural defenses, leading to a larger quantity of neoplasms comprising both nonaggressive and aggressive ones to regularly emerge and progress. If our hypothesis is correct, testing would require the consideration of the raw quantity, not the relative frequency, of aggressive cancers in obese patients compared with lean ones. We also discuss the possibility that in obese persons, nonaggressive malignancies may prevent the subsequent progression of aggressive cancers through negative competitive interactions between tumors.

Genetic risk assessment of thrombophilia in patients with adverse obstetric outcomes

OBJECTIVES

To investigate the incidence of inherited thrombophilias in patients with adverse obstetric outcomes and to compare detection rates of thrombophilias between standard blood tests and a novel genetic test.

METHODS

This is a case-control prospective study performed in Hospital Sant Joan de Déu in Barcelona, Spain. Cases had a history of intrauterine growth restriction requiring delivery before 34 weeks gestation, placental abruption before 34 weeks gestation, or severe preeclampsia. Controls had at least two normal, spontaneously conceived pregnancies at term, without complications or no underlying medical disease. At least 3 months after delivery, all case and control women underwent blood collection for standard blood tests for thrombophilias and saliva collection for the genetic test, which enables the diagnosis of 12 hereditary thrombophilias by analyzing genetic variants affecting different points of the blood coagulation cascade.

RESULTS

The study included 33 cases and 41 controls. There were no statistically significant differences between cases and controls in the standard blood tests for thrombophilias in plasma or the TiC test for genetic variables. One clinical-genetic model was generated using variables with the lowest P values: ABO, body mass index, C_rs5985, C_rs6025, and protein S. This model exhibited good prediction capacity, with an area under the curve of almost 0.7 (P <0.05), sensitivity of almost 67%, and specificity of 70%.

CONCLUSION

Although some association may exist between hypercoagulability and pregnancy outcomes, no significant direct correlation was observed between adverse obstetric outcomes and inherited thrombophilias when analyzed using either standard blood tests or the genetic test. Future studies with a larger sample size are required to create a clinical-genetic model that better discriminates women with a history of adverse pregnancy outcomes and an increased risk of poor outcomes in subsequent pregnancies.

Predictors and outcomes of disseminated tuberculosis in an intermediate burden setting

SETTING

University-affiliated hospital located in Porto, North Portugal, an area with a low to intermediate incidence of tuberculosis (TB).

OBJECTIVE

To identify predictors and outcomes of disseminated TB (dTB).

DESIGN

A cohort of patients diagnosed with TB between 2007 and 2013 was retrospectively analysed. Patients with dTB criteria were characterized and compared to single organ TB cases. Factors independently associated with dTB were determined by multivariate logistic regression analysis.

RESULTS

A total of 744 patients were analysed, including 145 with dTB. Independent risk factors for dTB were pharmacological immunosuppression (OR 5.6, 95% CI 2.8-11.3), HIV infection (OR 5.1, 95% CI 3.1-8.3), chronic liver failure or cirrhosis (OR 2.3, 95% CI 1.4-4.1) and duration of symptoms (OR 2.3, 95% CI 1.4-3.8). Compared to single organ TB, the clinical presentation of dTB patients differed by the absence of haemoptysis (OR 3.2, 95% CI 1.3-8.4) and of dyspnoea (OR 1.9, 95% CI 1.2-3.1), presence of weight loss (OR 1.8, 95% CI 1.1-2.9), night sweats (OR 1.7, 95% CI 1.1-2.7) and bilateral lung involvement (OR 4.4, 95% CI 2.8-7.1). Mortality and time until culture conversion were higher for dTB patients, although not reaching statistical significance.

CONCLUSION

Immunosuppressive conditions and chronic liver failure or cirrhosis were associated with increased risk of dTB. The haematogenous spread may be dependent on longer symptomatic disease and usually progresses with bilateral lung involvement.

Occluding junctions as novel regulators of tissue mechanics during wound repair

Simple epithelial repair is mediated by the contraction of an actomyosin cable and cellular rearrangements at the wound edge. Carvalho et al. show that occluding junctions are required for epithelial repair by regulating these cellular rearrangements and tissue mechanical properties.

In epithelial tissues, cells tightly connect to each other through cell–cell junctions, but they also present the remarkable capacity of reorganizing themselves without compromising tissue integrity. Upon injury, simple epithelia efficiently resolve small lesions through the action of actin cytoskeleton contractile structures at the wound edge and cellular rearrangements. However, the underlying mechanisms and how they cooperate are still poorly understood. In this study, we combine live imaging and theoretical modeling to reveal a novel and indispensable role for occluding junctions (OJs) in this process. We demonstrate that OJ loss of function leads to defects in wound-closure dynamics: instead of contracting, wounds dramatically increase their area. OJ mutants exhibit phenotypes in cell shape, cellular rearrangements, and mechanical properties as well as in actin cytoskeleton dynamics at the wound edge. We propose that OJs are essential for wound closure by impacting on epithelial mechanics at the tissue level, which in turn is crucial for correct regulation of the cellular events occurring at the wound edge.

Segmentation of the Globus Pallidus Internus Using Probabilistic Diffusion Tractography for Deep Brain Stimulation Targeting in Parkinson Disease

BACKGROUND AND PURPOSE

Although globus pallidus internus deep brain stimulation is a widely accepted treatment for Parkinson disease, there is persistent variability in outcomes that is not yet fully understood. In this pilot study, we aimed to investigate the potential role of globus pallidus internus segmentation using probabilistic tractography as a supplement to traditional targeting methods.

MATERIALS AND METHODS

Eleven patients undergoing globus pallidus internus deep brain stimulation were included in this retrospective analysis. Using multidirection diffusion-weighted MR imaging, we performed probabilistic tractography at all individual globus pallidus internus voxels. Each globus pallidus internus voxel was then assigned to the 1 ROI with the greatest number of propagated paths. On the basis of deep brain stimulation programming settings, the volume of tissue activated was generated for each patient using a finite element method solution. For each patient, the volume of tissue activated within each of the 10 segmented globus pallidus internus regions was calculated and examined for association with a change in the Unified Parkinson Disease Rating Scale, Part III score before and after treatment.

RESULTS

Increasing volume of tissue activated was most strongly correlated with a change in the Unified Parkinson Disease Rating Scale, Part III score for the primary motor region (Spearman r = 0.74, P = .010), followed by the supplementary motor area/premotor cortex (Spearman r = 0.47, P = .15).

CONCLUSIONS

In this pilot study, we assessed a novel method of segmentation of the globus pallidus internus based on probabilistic tractography as a supplement to traditional targeting methods. Our results suggest that our method may be an independent predictor of deep brain stimulation outcome, and evaluation of a larger cohort or prospective study is warranted to validate these findings.

Cellular and Clinical Pharmacokinetic/Pharmacodynamic Basis for Lack of Efficacy of 21-Day Continuous Topotecan in Patients with Untreated Advanced Adenocarcinoma of the Pancreas

Background

In a phase II study, topotecan was evaluated for response and toxicity in patients with advanced pancreatic carcinoma at the schedule of 0.7 mg/m2/day q 21 days q 28 days.

Methods

Responses were assessed after at least 2 courses using WHO criteria, and toxicity was evaluated after each course according to the CTC-NCI standards. Between December 1995 and September 1997, 15 assessable patients (median age, 55 years; range, 36-74; median ECOG performance, 1; range, 0-3) were included in the study. All had biopsy-proven and measurable disease, a life-expectancy of at least 3 months, and normal bone marrow, liver, and renal function. None of the patients had undergone prior cytotoxic or radiation therapy, and 10 were initially treated by surgery. Twenty-five cycles were assessable for toxicity. Plasma was collected from 7 patients who had received a total of 10 cycles and was, after extraction with methanol at −20°C, analyzed for total topotecan by an HPLC method. The thus determined steady-state concentrations were assessed for their capacity to affect growth and DNA integrity in the BxPC-3 human pancreatic carcinoma cell line after 21 days of continuous exposure. For these purposes, we used a sulforhodamine B staining assay, and agarose gel electrophoresis, respectively.

Results

Grades 3-4 leukopenia, thrombocytopenia, granulocytopenia, and anemia occurred in 8, 6, 8 and 8 cycles, respectively. Other mild to moderate side effects (grades 1-2) included malaise, nausea and vomiting, anorexia, and alopecia. No objective tumor response was documented. HPLC analysis of patients' plasma showed the attainment of constant steady-state levels of 1.0 ± 0.1 ng/mL during the entire infusion period. At such a concentration, topotecan did not significantly affect growth or DNA integrity in the BxPC-3 cells. Fifty percent cell growth inhibition and appreciable oligonucleosomal DNA fragmentation were only evident with 21 days topotecan ≥ 50 ng/mL.

Conclusions

Our data suggest that the lack of clinical activity of 0.7 mg/m2 daily topotecan for 21 days q 28 days in patients with advanced pancreatic carcinoma might be partially attributed to the achievement of non-tumoricidal plasma drug concentrations.

Anti-oxidants correct disturbance of redox enzymes in the hearts of rat fetuses with congenital diaphragmatic hernia

AIM

To evaluate if the redox system is unbalanced in the hearts of nitrofen-induced congenital diaphragmatic hernia  (CDH) animals and to study the possible preventive effects of two anti-oxidant treatments, apocynin and epigallocatechin-3-gallate (EGCG).

METHODS

Adult rats were divided into four groups. Group 1: rats received only vehicle on day E9.5. Group 2: rats received 100 mg nitrofen on day E9.5. Group 3: 1 month before mating rats received apocynin 1.5 mM and, when pregnant, 100 mg nitrofen on day E9.5. Group 4: same than group 3 but with EGCG 30 mg/kg. All fetuses were recovered at term and the hearts were processed. Nox activity and mRNA levels of Nox1, Nox2, Nox4, SOD1, SOD2, SOD3, catalase, and GPX1 were analyzed. Nox, SOD, and Catalase activity and H2O2 production were also evaluated.

RESULTS

Nox activity, H₂O₂ production and Nox1, Nox2, and Nox4 mRNA levels were increased in the hearts of fetuses with CDH. There were no changes in SOD1 levels, whereas those of SOD2, SOD3, catalase, and GPX1 mRNA were decreased. Apocynin and EGCG treatments attenuated the increment of Nox and SOD activities and H₂O₂ production was only decreased by apocynin.

CONCLUSION

These findings suggest a possible preventive effect on the abnormal redox metabolism of anti-oxidant treatments in the hearts from rat fetuses with CDH. If the same occurs in humans, it could represent a potential tool in future prenatal treatment.

Combination of etoposide and fisetin results in anti-cancer efficiency against osteosarcoma cell models

Osteosarcoma chemotherapy is often limited by chemoresistance, resulting in poor prognosis. Combined chemotherapy could, therefore, be used to prevent resistance to chemotherapeutics. Here, the effects of fisetin on osteosarcoma cells were investigated, as well as cytostatic potential in combination with the anti-cancer drug etoposide. For this, different osteosarcoma cell lines were treated with fisetin, with etoposide and with respective combinations. Fisetin was associated with decrease in colony formation in Saos-2 and in U2OS cells but not in MG-63 cells. Notwithstanding, upon evaluation of cellular growth by crystal violet assay, MG-63 and Saos-2 cells showed decreased cell proliferation at 40 and 20 µM fisetin, respectively. Depending on the relative concentrations, fisetin:etoposide combinations showed negative-to-positive interactions on the inhibition of cell proliferation. In addition, fisetin treatment up to 50 µM for 48 h resulted in G2-phase cell cycle arrest. Regardless of the combination, fisetin:etoposide increased % cells in G2-phase and decreased % cells in G1-phase. In addition, mixtures with more positive combined effects induced increased % cells in S-phase. Compared to etoposide treatment, these combinations resulted in decreased levels of cyclins B1 and E1, pointing to the role of these regulators in fisetin-induced cell cycle arrest. In conclusion, these results show that the combination of fisetin with etoposide has higher anti-proliferative effects in osteosarcoma associated with cell cycle arrest, allowing the use of lower doses of the chemotherapeutic agent, which has important implications for osteosarcoma treatment.

Macular choroidal thickness after vitreoretinal surgery: Long-term effect of pars plana vitrectomy with and without encircling scleral buckling surgery

PURPOSE

To evaluate the macular choroidal thickness (CT) of eyes subjected to pars plana vitrectomy (PPV) whether or not combined with encircling scleral buckling (ESB) surgery for primary rhegmatogenous retinal detachment repair at 6 months or more after surgery.

METHODS

This observational study included: 15 eyes (15 patients) submitted to combined ESB+PPV; 15 eyes submitted to PPV and their respective 30 normal fellow eyes (FE). Two 6mm lineal perpendicular optical coherence tomography B-scans centred on the fovea with enhanced depth imaging were performed on each eye. CT was measured at several macular locations: subfoveal (SF-CT) and at a radius of 1, 2, and 3mm from the fovea. CTs of the eyes in the CE+PPV group were compared to CT in the PPV group and the CTs of all operated eyes were compared to the CTs of their FE.

RESULTS

SF-CT of the eyes in the ESB+PPV group was significantly increased compared to their FE (P=.001). CT at a radius of 1, 2, and 3mm from the fovea of the ESB+PPV group were significantly increased (P=.001, P=.005, and P=.001, respectively). The SF-CT of the PPV group was similar to their FE (P=.691). The SF-CT of the ESB+PPV group was significantly increased compared to SF-CT of the PPV group (P=.019).

CONCLUSIONS

The CT of the eyes subjected to combined ESB and PPV was significantly increased at 6 months or more after surgery compared to the CT of their FE and to the CT of the eyes subjected to PPV alone, which could be explained by a venous engorgement caused by the ESB.