A Comprehensive, FAIR File Format for Neuroanatomical Structure Modeling

With advances in microscopy and computer science, the technique of digitally reconstructing, modeling, and quantifying microscopic anatomies has become central to many fields of biological research. MBF Bioscience has chosen to openly document their digital reconstruction file format, the Neuromorphological File Specification, available at www.mbfbioscience.com/filespecification (Angstman et al., 2020). The format, created and maintained by MBF Bioscience, is broadly utilized by the neuroscience community. The data format's structure and capabilities have evolved since its inception, with modifications made to keep pace with advancements in microscopy and the scientific questions raised by worldwide experts in the field. More recent modifications to the neuromorphological file format ensure it abides by the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles promoted by the International Neuroinformatics Coordinating Facility (INCF; Wilkinson et al., Scientific Data, 3, 160018,, 2016). The incorporated metadata make it easy to identify and repurpose these data types for downstream applications and investigation. This publication describes key elements of the file format and details their relevant structural advantages in an effort to encourage the reuse of these rich data files for alternative analysis or reproduction of derived conclusions.

UV/Vis absorption spectroelectrochemistry of folic acid

UV/Vis absorption spectroelectrochemistry is a very promising analytical technique due to the complementary information that is simultaneously obtained from electrochemistry and spectroscopy. In this work, this technique is used in a parallel configuration to study the oxidation of folic acid in alkaline medium. Herein, UV/Vis absorption spectroelectrochemistry has been used to detect both the oxidation products and the folic acid consumed at the electrode/solution interface, allowing us to develop an analytical protocol to quantify vitamin B9 in pharmaceutical tablets. Linear ranges of three orders of magnitude have been achieved in basic medium (pH = 12.9), obtaining high repeatability and low detection limits. The spectroelectrochemical determination of folic acid in pharmaceutical tablets at alkaline pH values is particularly interesting because of the changes that occur in the optical signal during the electrochemical oxidation of FA, providing results with very good figures of merit and demonstrating the utility and versatility of this hyphenated technique, UV/Vis absorption spectroelectrochemistry.

A global approach to improving penile cancer care

Rare tumours such as penile carcinoma have been largely neglected by the urology scientific community in favour of more common - and, therefore, more easily fundable - diseases. Nevertheless, penile cancer represents a rising burden for health-care systems around the world, because a lack of widespread expertise, ineffective centralization of care and absence of research funds have hampered our ability to improve the global care of these patients. Moreover, a dichotomy has arisen in the field of penile cancer, further impeding care: the countries that are mainly supporting research on this topic through the development of epidemiological studies and design of clinical trials are not the countries that have the highest prevalence of the disease. This situation means that randomized controlled trials in developed countries often do not meet the minimum accrual and are intended to close before reaching their end points, whereas trials are almost completely absent in those areas with the highest disease prevalence and probability of successful recruitment, such as Africa, South America and South Asia. The scientific and organizational inaction that arises owing to this mismatch translates into a burdensome cost for our patients. A global effort to gather experts and pull together scientific data from around the world may be the best way to boost clinical research, to change clinical practice and, ultimately, to improve care for patients and their families.

Higher frequency of comorbidities in fully vaccinated patients admitted to ICU due to severe COVID-19: a prospective, multicenter, observational study

The coronavirus disease 2019 (COVID-19) vaccination campaign in Spain began on 27 December 2020 [1]. To date, more than 36 million people have been fully vaccinated, with most of the population, namely 25.3 million people (69.1%), receiving BNT 162b2 (Pfizer/BioNTech) [1]. With respect to other vaccines and figures, 4.8 million (13.2%) people have received AZD1222 (Oxford/AstraZeneca); 4.5 million (12.3%) mRNA-1273 (Moderna); and 2.0 million (5.4%) JNJ-78436735 (Janssen) [1].

Severe COVID-19 disease requiring ICU admission is possible in the fully vaccinated population, especially in those with immunocompromised status and other comorbidities. Interventions to improve vaccine response might be necessary in this population.https://bit.ly/3Fw6vCP

Clinical risk factors for early mortality in patients with community-acquired septic shock. The importance of adequate source control

OBJECTIVE

To evaluate the incidence and risk factors for early mortality (EM) in the ICU in patients with community-acquired septic shock (CASS).

DESIGN

A retrospective cohort study of patients with CASS admitted to the ICU (2003-2016).

SETTING

ICU at a University Hospital in Spain.

PATIENTS

All consecutive patients admitted to the ICU with CASS.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

CASS was defined according to the Sepsis-3 definitions. EM were defined as occurring within of 72h following ICU admission. A multinomial logistic regression analysis was performed to identify the risk factors associated with early deaths.

RESULTS

During the study period, 625 patients met the Sepsis-3 criteria and admitted with CASS. 14.4% of all patients died within the first 72h. Of 161 patients who died in the ICU, 90 (55.9%) died within the first 72h. The percentage of early and late mortality did not vary significantly during the study period. The need and adequacy of source control were significantly lower in patients with EM. In the multivariate analysis, ARDS, non-respiratory infections, bacteremia and severity at admission were variables independently associated with EM. The only factor that decreased EM was adequate source control in patients with infections amenable to source control.

CONCLUSIONS

The incidence of EM has remained stable over time, which means that more than half of the patients who die from CASS do so within the first 72h. Infections where adequate source control can be performed have lower EM.

Thermodynamic and Transport Properties of LiF and FLiBe Molten Salts with Deep Learning Potentials

Molten salts have attracted interest as potential heat carriers and/or fuel solvents in the development of new Gen IV nuclear reactor designs, high-temperature batteries, and thermal energy storage. In nuclear engineering, salts containing lithium fluoride-based compounds are of particular interest due to their ability to lower the melting points of mixtures and their compatibility with alloys. A machine learning potential (MLP) combined with a molecular dynamics study is performed on two popular molten salts, namely, LiF (50% Li) and FLiBe (66% LiF and 33% BeF₂), to predict the thermodynamic and transport properties, such as density, diffusion coefficients, thermal conductivity, electrical conductivity, and shear viscosity. Due to the large possibilities of atomic environments, we employ training using Deep Potential Smooth Edition (DPSE) neural networks to learn from large datasets of 141,278 structures with 70 atoms for LiF and 238,610 structures with 91 atoms for FLiBe molten salts. These networks are then deployed in fast molecular dynamics to predict the thermodynamic and transport properties that are only accessible at longer time scales and are otherwise difficult to calculate with classical potentials, ab initio molecular dynamics, or experiments. The prospect of this work is to provide guidance for future works to develop general MLPs for high-throughput thermophysical database generation for a wide spectrum of molten salts.

Health workers' perspectives on asthma care coordination between primary and specialised healthcare in the COVID-19 pandemic: a protocol for a qualitative study in Ecuador and Brazil

INTRODUCTION

Asthma is a common long-term disorder and strategies to improve asthma control are still a challenge. Integrated delivery of health systems is critical for effective asthma care: there is limited information on experiences of care coordination for asthma from Latin America, especially on perspectives of health personnel and in the context of the COVID-19 pandemic.

METHODS AND ANALYSIS

This protocol details a qualitative approach to analyse health workers' perspectives of healthcare coordination for asthma control during COVID-19 pandemic in Ecuador and Brazil, at primary and specialised levels, through in-depth semistructured interviews using a video communications platform. The analysis will identify knowledge and perspectives based on coordination of clinical information, clinical management and administrative coordination. Theoretical sampling will be used to obtain approximately equal numbers of women and men within each level of healthcare; data saturation will be used to determine sample size. Transcripts will be analysed using content-coding procedures to mark quotations related to major topics and subthemes included in the interview guide, and narrative analysis will be based on a theoretical framework for healthcare coordination to identify new themes and subthemes.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the ethics committees of Hospital General Docente Calderón, Quito, Ecuador; and Universidade Federal da Bahia, Salvador, Brazil. The findings of this study will be disseminated through peer-reviewed articles, conference presentations and condensed summaries for key stakeholders and partners.

Co-designing a training package to promote health/oral health for people experiencing homelessness

Background

In Scotland, 31,333 households were assessed as experiencing homelessness in 2019/20. This population present high morbidity and mortality which is a public health issue. Their health needs have been identified within Scottish policy as part of the broad goal of reducing inequalities and poverty. Those experiencing homelessness face multiple exclusions that must be addressed by practitioners from all health and social care sectors. Frontline staff have identified they often do not have adequate information and/or training on wider health issues linked with their client's needs. The aim of this research is to co-produce training resources to support front-line staff to discuss and to promote health and oral health.

Methods

Community-based participatory research that used online workshops to listen to the views of people with lived experience, practitioners and students from health and third sector, and policy makers regarding accessibility of services and practitioner approach towards those experiencing homelessness. Content analysis will be used to identified recurrent themes.

Results

The preliminary findings shown that lack of empathy from practitioners, continuity of care and stigma are barriers to access services. This is informing a co-designed knowledge exchange training packaged to help practitioners to improve knowledge and ability to promote health/oral health and to engage with people experiencing homelessness or at risk of becoming homeless. Educational materials (e-book on health promotion, comics books on barriers to access services, and a guide to promote oral health) compose this training package.

Conclusions

The training package allows adaptations to different settings and contexts and will be an important resource to be used by practitioners from different fields to prevent and tackle homelessness. Participants are sharing important views related to the need of a human rights and social justice-based approach to health promotion.

Key messages

Development of a co-designed knowledge exchange training package to improve practitioners' knowledge and ability to communicate and to engage with people experiencing homelessness. To empower people experiencing homelessness regarding positive health/oral health behavior change.

Healthcare needs of young people transitioning back to the community after a custodial sentence

Background

People in prison have poorer health outcomes than the general population, added by the long-term impact of incarceration on mortality. Young people in custody face extra challenges associated with the stage of development. There is a lack of a tailored approach and policy to young people when transitioning back to the community. This paper draws from a PhD research that looked at the challenges to access healthcare during the transition back to the community. The specific question is: What are young people's healthcare needs when released from custodial sentences?

Methods

An ethnographic study conducted in Scotland in partnership with a community-based organisation. The participants were eight young people and ten practitioners that work in health and social care. Participatory observation and in-depth interviews were used to collect data during July 2019 and March 2020. Data analysis was conducted with Reflexive thematic analysis. NVivo supported data management.

Results

The identified needs were individualised issues, structural factors, mental health, substance use and geographical disposition of services. There is a need for mental support and continuity of care associated with substance use. The demand for local services is vital for healthcare provision. Healthcare needs go beyond the necessity of services and health issues. They are associated with stigma in the interaction with practitioners. Institutional practices and practitioners' attitudes reinforce non-explicit forms of discrimination and health inequalities.

Conclusions

Practitioners and policymakers need to focus on the person-centred approach. They need to listen to young people. Data showed a need for specific services, like mental health and drug use. Moreover, practitioners need to avoid stigmatisation and discrimination by a caring practice. Public health and social care policies need to address stigma and access to services for young people after a custodial sentence.

Key messages

It is necessary to avoid stigmatisation and improve access to services for young people transitioning back to the community after a custodial sentence. Public Health and social care policies need to address this marginalised group by offering person-centred approaches, continuity of care and support during re-entry.

Altered atrial restitution dynamics and refractoriness in metabolic syndrome due to up-regulation of potassium repolarizing currents increases susceptibility to atrial fibrillation

Background

Metabolic alterations, such as Metabolic Syndrome (MS), describe an association of factors including diabetes, hypertension, obesity and dyslipidemia, linked to higher risk and prevalence of overall cardiovascular disease, arrhythmogenesis and sudden cardiac death. Obese and diabetic patients have shown an increased risk for developing atrial fibrillation (AF). However, underlying mechanisms are not understood.

Purpose

To study the effects of MS and obesity remodeling in atrial restitution dynamics, frequency-dependent adaptation, refractoriness and its potential susceptibility to AF.

Methods

Electrophysiological experimental data from High-fat (HF-O, standard rabbit chow with an additional 15% fat) and Hig-fat High-Sucrose Metabolic Syndrome (HFHS-MS, 10% hydrogenated coconut oil and 5% lard, 15% high-sucrose dissolved in water) rabbit models were used to adjust computational models atrial electrophysiology remodeling under each condition. Additionally, isoproterenol and AF conditions were considered to challenge both in-silico models. Validation and sensitivity analysis were performed for each model parameters. Computational simulations in conditions of pacing at different pacing cycle lengths was assessed at 100, 125, 150, 200, 250, 350, 450, 500, 650, 750, 850, 1000 ms. Restitution dynamics were automatically determined and analyzed, as well as restitution slopes and presence of automaticity, early after-depolarizations, alternans and cardiac arrhythmia induction.

Results

Shortening of action potential duration and refractoriness in the left atrium was observed under HFHS-MS. Upstroke velocity, maximum excitability and sodium availability were altered both in HF-O and HFHS-MS. HF-O remodeling showed presence of alternans at high pacing frequencies. Repolarization restitution was shortened in conditions of ISO and MS-AF. Restitution slopes were >1 in HF-O and HFHS-MS, which was correlated to higher susceptibility to AF, and further increased in MS-AF. Under MS-AF, abbreviation in APD in both atria, resulted in increased reentrant frequencies in AF, which was exacerbated under IK1 up-regulation, increasing atrial vulnerability.

Conclusions

HFHS-MS underlies modifications in atrial electrophysiology including shorter refractoriness in HFHS-MS, as well as modifications in atrial excitability, which may be pro-arrhythmic mainly at high frequency rates. This could be explained in part by an up-regulation of outward potassium channels. These results could partially explain increased susceptibility for AF in MS.

Funding Acknowledgement

Type of funding sources: None.

Long-term outcomes among a cohort of 4296 implantable cardioverter-defibrillator patients: insights from the UMBRELLA study

Background

Large observational real-world studies describing modern implantable cardioverter-defibrillator (ICD) populations with long-term follow-up are lacking.

Purpose

To assess the incidence of arrhythmias in a cohort of contemporary patients undergoing ICD implant from 2005 and 2017 and to analyze the arrhythmic risk and mortality according to their clinical profiles.

Methods

UMBRELLA (NTC01561144) is a prospective, multicentre, nationwide study of ICD patients followed by remote monitoring. All device information was automatically stored through the remote monitoring system and a blinded review of all the stored arrhythmic episodes was performed. The study outcomes were first appropriate ICD therapy and all-cause death.

Results

The study population consisted of 4296 patients (61.9±12.9 years, ischaemic cardiomyopathy (ICM): n=2150, dilated cardiomyopathy (DCM): n=1166, valvular heart disease (VHD): n=119, hypertrophic cardiomyopathy (HCM): n=294, arrhythmogenic right ventricular cardiomyopathy (ARVC): n=71, Brugada syndrome (BS): n=143, long QT syndrome (LQTS): n=43, and adult congenital heart disease (ACHD): n=60)). Primary prevention (PP) was the main indication (n=2758).

During a mean follow-up of 46.6±27.3 months, 16,067 episodes of sustained ventricular arrhythmia (SVA) occurred in 1344 patients. Appropriate ICD therapy was delivered to 85.7% (n=13,767) episodes of SVA in 1173 patients (27.3% of population). A higher risk of first appropriate ICD therapy was observed in VHD (HR: 1.94, 95% CI: 1.43–2.62), ARVC (HR: 1.84, 95% CI: 1.28–2.66), ICM (HR: 1.51, 95% CI: 1.29–1.78), and DCM (HR: 1.28, 95% CI: 1.07–1.53) whereas patients with HCM (HR: 0.72, 95% CI: 0.54–0.96) and BS (HR: 0.25, 95% CI: 0.14–0.45) were at significantly lower risk (Figure 1A). In multivariate analysis (Table 1), age, gender, atrial fibrillation (AF), secondary prevention, LVEF ≤35%, and QRS width emerged as clinical predictors of appropriate ICD therapy, whereas CRT-D correlated with lower risk. An independently higher risk was found in DCM, VHD, and ARVC, and a lower risk in BS patients.

At follow-up, 590 deaths (13.4% of population) were reported. Patients with ICM (HR 3.90, 95% CI: 2.58–5.90), DCM (HR 3.33, CI 95%: 2.18–5.10), and VHD (HR 3.97, CI 95%: 2.25–6.99) had worse prognoses and it was significantly better in BS patients (HR 0.11, 95% CI: 0.01–0.67, p=0.017) (Figure 1B). In multivariate analysis, age, gender, AF, renal failure, diabetes and reduced LVEF, emerged as independent predictors of all-cause death (Table 1).

Conclusions

Irrespective of the aetiology, contemporary ICD patients with an arrhythmic substrate derived from left ventricular systolic dysfunction had a similar risk of ICD life-saving interventions and death.

Funding Acknowledgement

Type of funding sources: None. Table 1Figure 1

Asthma, rhinitis and eczema symptoms in Quito, Ecuador: a comparative cross-sectional study 16 years after ISAAC

Background

In 2003, the International Study of Asthma and Allergies in Childhood (ISAAC) estimated the prevalence of asthma, rhinitis and eczema symptoms in Quito, Ecuador. Since then, no update of this study has been done in the last years. This study examined changes in the prevalence of asthma–rhinitis–eczema symptoms over a 16 years period in Quito and explored possible risk factors.

Methods

We conducted a comparative cross-sectional study in an adolescent population following the Global Asthma Network (GAN) methodology. A written questionnaire was used to explore symptoms of asthma–rhinitis–eczema. We calculated the prevalence and 95% CIs for each of the symptoms and compared them with the ISAAC results. We conducted bivariate and multivariate analysis using logistic regression to identify possible risk factors for recent wheeze, rhinitis and eczema.

Results

A total of 2380 adolescents aged between 13 and 14 years were evaluated. The prevalence of doctor diagnosis for asthma, rhinitis and eczema was 3.4%, 8.5% and 2.2%, respectively. Compared with ISAAC results, we found a lower prevalence of wheeze and eczema symptoms: wheeze ever (37.6% vs 12.7%), recent wheeze (17.8% vs 6.5%), asthma ever (6.9% vs 4.6%), recent rush (22.4% vs 13.9%) and eczema ever (11.7% vs 3.6%). The prevalence of rhinitis symptoms in the GAN study was higher than the ISAAC results: nose symptoms in the past 12 months (36.6% vs 45.8%) and nose and eye symptoms in the past 12 months (23.1% vs 27.9). Significant associations were observed between symptoms of asthma–rhinitis–eczema and sex, race/ethnicity, smoking habit, physical exercise and sedentary activities.

Conclusions

In the last two decades, the prevalence of asthma and eczema symptoms in adolescent population in the city of Quito has significantly declined; however, the prevalence of rhinitis symptoms has increased. The reduction in asthma symptoms could be related to better managing the disease and changes in local environmental risk factors in the last years. Further studies must be conducted in the country to evaluate the change in trends in asthma and other related allergic diseases.

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background

Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission.

Methods

Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes.

Results

Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO₂/FiO₂ increased from 115.6 [80.0–171.2] to 180.0 [135.4–227.9] mmHg and the ventilatory ratio from 1.73 [1.33–2.25] to 1.96 [1.61–2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01–1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01–1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93–1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO₂/FiO₂ variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47).

Conclusions

Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO₂/FiO₂ variation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03727-x.

Étude observationnelle d’évolution de la COVID-19 dans une population de patients hémodialysés avec étude d’impact des comorbidités

Introduction

Nos patients dialysés ont été particulièrement exposés à la pandémie de COVID-19.

Description

Nous rapportons une étude observationnelle rétrospective de notre cohorte de patients hémodialysés repliés en secteur COVID de mars 2020 à fin mars 2021 (1 an).

Méthodes

Nous avons observé dans cette population, l’âge, le sexe, l’ancienneté en dialyse, le type de variant si disponible, les comorbidités principales, la prise d’immunosuppresseurs, l’existence d’une néoplasie active, la présence d’un diabète, d’un terrain vasculaire sévère, d’une pathologie respiratoire, le lieu de vie, les symptômes au moment du diagnostic, la prise en charge et l’évolution.

Résultats

Sur cette cohorte de 122 patients, l’âge moyen est de 71 ans (médiane 72,5 ans), 11 (9 %) vivaient en EHPAD, l’ancienneté moyenne en dialyse est de 9,5 ans (médiane 6,35 ans). Quatre-vingt-douze ont contracté le virus historique (α), 15 le variant β, 3 le variant γ et 12 n’ont pas été qualifiés. Quatre patients (3 %) étaient sous immunosuppresseurs, 9 (7 %) avaient une néoplasie active dont 2 sont décédés, 58 (47,5 %) étaient diabétiques, 15 (12 %) présentaient une pathologie respiratoire dont 4 sont décédés, 86 (70,5 %) un terrain vasculaire sévère dont 18 sont décédés sur 19 décès au total. L’IMC moyen était de 26,7 (médiane 25,8). Cinq parmi les 22 patients avec troubles cognitifs sont décédés.

Soixante (49 %) ont été pris en charge à domicile.

Quarante-deux (34,4 %) patients ont été hospitalisés, 20 en réanimation dont 8 sont décédés.

Quarante-six (37,5 %) patients ont développé une forme asymptomatique, 25 (20,5 %) une forme modérée, 32 (26 %) une forme sévère et 12 (10 %) une forme grave d’emblée.

La mortalité est de 15,5 % (19 patients décédés).

Conclusion

Dans notre cohorte, la prise d’immunosuppresseurs, les troubles cognitifs, ou l’institutionnalisation ne semblent pas être des facteurs aggravants. En revanche, le terrain vasculaire sévère semble être un élément de gravité.

Ab Initio Energetic Barriers of Gas Permeation across Nanoporous Graphene

Realizing membranes of atomic thickness functioning reliably constitutes a giant leap forward for a plethora of applications where the efficient separation of fluid constituents at the molecular level is critical. Here, by employing density functional theory, we explore the energy landscape of typical gas molecules attempting permeation through graphene nanopores and determine the minimum energy permeation pathways, based on the precise knowledge of the related molecular level interactions. With this approach we investigate two basic permeation routes: direct permeation and surface-based transport. We find that for subnanometer pores, the diffusion barrier of direct and surface transport depends on the pore chemical functionalization, while the molecule pore permeation barrier is independent of the gas-pore approach due to the overlap of surface and direct diffusion paths over the pore center. The overall minimum energy permeation pathway of He, H₂, CO₂, and CH₄ molecules, across nanopores of different dimensions and chemical functionalization, defines the pore diameter (∼1.2 nm) below which effusion theory is inaccurate, as well as the critical pore diameter (∼0.8 nm) required to achieve positive permeation barriers driving molecular sieving. We determine that achieving positive permeation barriers required for high selectivity gas separation is inseparably combined with postpermeation desorption barriers due to attractive van der Waals interactions. The discovered permeation energetics are pore-molecule-specific and are incorporated into an analytical model extending existing theory. Our results provide a scientific background for rational pore design in graphene membranes, which can lead to gas separation at a commercially relevant performance level.

Operational Variables on the Processing of Porous Titanium Bodies by Gelation of Slurries with an Expansive Porogen

Colloidal processing techniques, based on the suspension of powders in a liquid, are very versatile techniques to fabricate porous structures. They can provide customized pores, shapes and surfaces through the control of operational parameters, being the base of the alternative additive manufacture processes. In this work disperse and stable titanium aqueous slurries has been formulated in order to process porous materials by the incorporation of methylcellulose (MC) as a gelation agent and ammonium bicarbonate as an expansive porogen. After casting the slurries and heating at mild temperatures (60-80 °C) the methylcellulose gels and traps the gas bubbles generated by the ammonium bicarbonate decomposition to finally obtain stiff porous green structures. Using an experimental design method, the influence of the temperature as well as the concentration of gelation agent and porogen on the viscosity, apparent density and pore size distribution is analyzed by a second-order polynomial function in order to identifying the influence of the operating variables in the green titanium porous compact. After sintering at 1100 °C under high vacuum, titanium sponges with 39% of open porosity and almost no close porosity were obtained.

P–079 A spontaneous LH peak before triggering for intrauterine insemination with donor sperm (IUI-D) is associated to lower live birth rates

Study question

Are live birth rates after IUI with donor sperm (IUI-D) and controlled ovarian stimulation comparable between women with a spontaneous LH peak vs those without?

Summary answer

Biochemical, clinical, ongoing pregnancy rates and live birth rates were higher among women without an LH peak.

What is known already

It is common clinical practice to trigger ovulation in IUI cycles once specific criteria are met; if a natural LH surge appears, adjusting the IUI timing may become necessary. Pregnancy rates seem to be slightly better when IUI is scheduled in relation to the presence or absence of an LH peak in non-stimulated cycles. In IUI with stimulated cycles, however, there is no consensus in the medical literature regarding the best moment to program the IUI, due to different inclusion criteria, different IUI timing and definition of LH peak among studies.

Study design, size, duration

Retrospective cohort study of 9,657 IUI-D cycles performed between 2012 and 2019 in one fertility center. IUI-D without LH peak (n = 6,679) versus IUI-D with LH peak (n = 2,978) were compared. Differences in pregnancy outcomes between study groups were evaluated using a Pearson’s Chi2 test. A p < 0.05 was considered statistically significant.

Participants/materials, setting, methods

The definition used to define an LH peak is > 10UI/L in the last follicular control. In cases without an LH peak, when at least one dominant follicle reached 17mm, ovulation was triggered with human chorionic gonadotropin in the following 24h, and IUI-D was performed 38h after triggering. In cases with an LH peak, ovulation was triggered the 6h following the detection, and IUI-D was also performed 38h later.

Main results and the role of chance

The women BMI and age were comparable between groups, with a mean±SD of 35.2±4.8 years old, and 24.3±4.7 for BMI. Other characteristics such as number of previous inseminations, type of stimulation drug, initial dose, total dose, stimulation length and number of follicles > 16mm in the last follicular control were also comparable. As expected, the LH level at the last follicular control was different between groups, with a mean of 5.1UI/L in the no-LH peak and 21.4IU/L in the LH peak group. The group without an LH peak had higher biochemical, clinical, ongoing and live birth rates compared to the group with LH peak: 27.7% vs. 20.7%; 19.5% vs. 15.5%; 17.7% vs. 13.7%; 16.3% vs. 12.6%, respectively (p-value<0.001).

Limitations, reasons for caution

The main limitation of the study is its retrospective nature. Also, a definition of LH peak based in absolute values was used; a definition based in relative values may lead to different results.

Wider implications of the findings: A definition of LH peak based on absolute numbers is imprecise, and the cut-off of 10UI/L does not allow a good scheduling for IUI. A LH peak based on relative values could improve the detection of patients starting ovulation and the accuracy in programming IUI.

Trial registration number

Not applicable

O-171 Altered meiotic spindle morphology and composition in in vitro matured oocytes

Study question

How does the meiotic spindle tubulin PTMs of MII oocytes matured in vitro compare to that of MII oocytes matured in vivo?

Summary answer

MII cultured in vitro present detyrosinated tubulin in the spindle microtubules, while MII oocytes matured in vivo do not.

What is known already

A functional spindle is required for chromosomal segregation during meiosis, but the role of tubulin post-translational modifications (PTMs) in spindle meiotic dynamics remains poorly characterized. In contrast with GVs matured in vitro within the cumulus oophorous, in vitro maturation of denuded GVs to the MII stage (GV-MII) is associated with spindle abnormalities, chromosome misalignment and compromised developmental potential. Although aneuploidy rates in GV-MII are not higher than in vivo matured MII, disorganized chromosomes may contribute to compromised developmental potential. However, to date, spindle PTMs morphology of GV-MII has not been compared to that of in vivo cultured MII oocytes.

Study design, size, duration

GV (n = 125), and MII oocytes (n = 24) were retrieved from hormonally stimulated women, aged 20 to 35 years old. GVs were matured to the MII stage in vitro in G-2 PLUS medium for 30h; the maturation rate was 68,2%; the 46 GV-MII oocytes obtained were vitrified, stored, and warmed before fixing and subjecting to immunofluorescent analysis. In vivo matured MII oocytes donated to research were used as controls.

Participants/materials, setting, methods

Women were stimulated using a GnRH antagonist protocol, with GnRH agonist trigger. Trigger criterion was ≥2 follicles ≥18mm; oocytes were harvested 36h later. Spindle microtubules were incubated with antibodies against alpha tubulin and tubulin PTMs (acetylation, tyrosination, polyglutamylation, Δ2-tubulin, and detyrosination); chromosomes were stained with Hoechst 33342 and samples subjected to confocal immunofluorescence microscopy (ZEISS LSM780), with ImageJ software analysis. Differences in spindle morphometric parameters were assessed by non-parametric Kruskal–Wallis and Fisher’s exact tests.

Main results and the role of chance

Qualitatively, Δ2-tubulin, tyrosination and polyglutamylation were similar for both groups. Acetylation was also present in both groups, albeit in different patterns: while in vivo matured MII oocytes showed acetylation at the poles, GV-MII showed a symmetrical distribution of signal intensity, but discontinuous signal on individual microtubule tracts, suggesting apparent islands of acetylation. In contrast, detyrosination was detected in in vivo matured MII oocytes but was absent from GV-MII. Regarding spindle pole morphology, of the four possible phenotypes described in the literature (double flattened and double focused; flattened-focused, focused-flattened, with the first word characterizing the cortex side of the spindle), we observed double flat shaped spindle poles in 86% of GV-MII oocytes (25/29) as opposed to 40.5% (15/37) for the in vivo matured MII oocytes (p = 0.0004, Fisher’s exact test). Further morphometric analysis of the spindle size (maximum projection, major and minor axis length) and the metaphase plate position (proximal to distal ratio, angle) revealed decreased spindle size in GV-MII oocytes (p = 0.019, non parametric Kruskal- Wallis test).

Limitations, reasons for caution

Oocytes retrieved from hyperstimulation cycles could be intrinsically impaired since they failed to mature in vivo. Our conclusions should not be extrapolated to IVM in non-stimulated cycles, as in this model, the cumulus oophorus is a major factor in oocyte maturation and correlation with spindle dynamics has been inferred.

Wider implications of the findings

The metaphase II spindle stability compared to the mitotic or metaphase I meiotic one justifies the presence of PTMs such as acetylation and glutamylation, which are found in stable, long-lived microtubules. The significance of the absence of detyrosinated microtubules in the MII-GV group remains to be determined

Trial registration number

not applicable

Major Adverse Cardiovascular Events During Invasive Pneumococcal Disease Are Serotype Dependent

BACKGROUND

Up to 30% of patients admitted to hospitals with invasive pneumococcal disease (IPD) experience major adverse cardiovascular event (MACE) including new/worsening heart failure, new/worsening arrhythmia, and/or myocardial infarction. Streptococcus pneumoniae (Spn) is the most frequently isolated bacterial pathogen among community-acquired pneumonia (CAP) patients and the only etiological agent linked independently to MACE. Nevertheless, no clinical data exist identifying which serotypes of Spn are principally responsible for MACE.

METHODS

This was an observational multicenter retrospective study conducted through the Public Health Secretary of Bogotá, Colombia. We included patients with a confirmed clinical diagnosis of IPD with record of pneumococcal serotyping and clinical information between 2012 and 2019. Spn were serotyped using the quellung method by the National Center of Microbiology. MACE were determined by a retrospective chart review.

RESULTS

The prevalence of MACE was 23% (71/310) in IPD patients and 28% (53/181) in patients admitted for CAP. The most prevalent S. pneumoniae serotype identified in our study was the 19A, responsible for the 13% (42/310) of IPD in our cohort, of which 21% (9/42) presented MACE. Serotypes independently associated with MACE in IPD patients were serotype 3 (odds ratio [OR] 1, 48; 95% confidence interval [CI] [1.21-2.27]; P = .013) and serotype 9n (OR 1.29; 95% CI [1.08-2.24]; P = .020). Bacteremia occurred in 87% of patients with MACE. Moreover, serum concentrations of C-reactive protein were elevated in patients with MACE versus in non-MACE patients (mean [standard deviation], 138 [145] vs 73 [106], P = .01).

CONCLUSIONS

MACE are common during IPD with serotype 3 and 9n independently of frequency.

Impact of COVID-19 pandemic on asthma symptoms and management: A prospective analysis of asthmatic children in Ecuador

Background

Asthma affects up to 33% of children in Latin American settings. The ongoing COVID-19 pandemic has had a significant impact on access to and use of health services. We aimed to evaluate the impact of the COVID-19 lockdown on asthma exacerbations, medical facility visits, and use of asthma medications in children.

Methods

We used data from a prospective cohort of 213 children aged 5–17 years in 3 Ecuadorian cities and analysed the impact of the COVID-19 lockdown on asthma. Outcomes (asthma exacerbations, emergency room [ER] visits, planned and unplanned outpatient visits, and use of inhaled corticosteroids and Beta-2 agonists) were analysed using repeated Poisson counts (ie, number of events per participant before and during the COVID-19 lockdown).

Results

During compared to before lockdown: a) the number of asthma exacerbations remained constant (IRR, 0.87; 95% CI: 0.72–1.05; p = 0.152); b) outpatient visits (IRR 0.26, 95% CI 0.14–0.47, p < 0.001) declined 74% while ER visits declined 89% (IRR 0.11, 95% CI 0.04–0.32, p < 0.001); and c) there was no change in inhaled corticosteroids use (IRR 1.03, 95% CI 0.90–1.16, P = 0.699) while Beta-2 agonist use increased (IRR 1.32, 95% CI 1.10–1.58, P = 0.003).

Conclusions

In a cohort of Ecuadorian children with asthma, health services attendance decreased dramatically after COVID-19 lockdown, but asthma exacerbations and use of inhaled corticosteroids were unchanged. Future analyses will address the question of the effect of SARS-CoV-2 infection on asthma exacerbations and control in this paediatric population.