Can static hyperinflation predict exercise capacity in COPD?

INTRODUCTION

The diagnosis and severity assessment of COPD relies on spirometry, and in particular the FEV1. However, it has been proposed that hyperinflation and air-trapping are better predictors of exercise capacity and mortality than the FEV1.

RESEARCH

QUESTION: Does static hyperinflation predict exercise capacity?

METHODS

We conducted an observational prospective study. Patients with COPD referred to the lung function laboratory were consecutively recruited. Patients with hyperinflation (the experimental group) were compared to patients without hyperinflation (the control group). The sample sizes were determined assuming an effect size of 0.5 and a power of 0.80.

RESULTS

We recruited 124 participants, of whom 87% were male, the mean age was 66.1 ± 8.8 years. 67% were symptomatic (GOLD B or D). Airflow limitation was moderate to severe in the majority of patients (median FEV1 47%, IQR 38-65%) and 43% of patients had static hyperinflation. The median 6MWD was 479 meters (404-510) and peak workload in CPET was 64 watts (46-88) with peak VO2 1.12 L/min, 0.89-1.31 L/min. Patients with lower FEV1, DLCO and IC/TLC and higher RV/TLC had reduced exercise capacity in both 6MWT and CPET, measured as lower distance, greater desaturation and ∆Borg dyspnoea, and reduced workload, peak VO2 and peak VE and higher desaturation and ventilatory limitation (VE/MVV). An IC/TLC < 0.33 predicted reduced exercise performance (peak O2 <60%). Dyspnoea assessed by mMRC and QoL measured by CAT and CCQ were also worse in the hyperinflation in COPD patients.

CONCLUSION

In COPD patients, IC/TLC and RV/TLC are valuable predictors of exercise performance in both 6MWT and CPET and PRO.

Peri-procedural, 30-day and 1 year-outcomes in chronic dialysis patients undergoing transcatheter aortic valve implantation

Background

Patients on chronic dialysis (CD) due to end-stage renal disease (ESRD) with symptomatic severe aortic stenosis eligible for transcatheter aortic valve implantation (TAVI) were excluded from randomized clinical trials. Our study aimed to investigate the outcomes of patients with chronic dialysis who underwent TAVI.

Methods

Single center analysis on prospectively collected data of all consecutive patients who underwent TAVI between January 2011 and December 2020 according to baseline renal function: chronic dialysis group (CD) and control group (CTRL). Procedural, 30-day and 1-year outcomes were assessed. Outcomes were defined in accordance with the VARC-3 criteria.

Results

A total of 875 patients underwent TAVI during the study period, of whom 22 (2.5%) were on chronic dialysis. Patients on CD were younger (median age 80 years, [IQR 73–84] vs 84 years, [IQR 80–87]; p&lt;0.001), more likely to be men [365/863 (42.8%) vs 18/22 (81.8%); p&lt;0.001] and more likely to have peripheral vascular disease [41/853 (4.8%) vs 7/22 (31.8%); p=0.031] and lower body mass index (median 24.1 kg/m2, [IQR 21.5–26.5] vs 26.3 kg/m2, [IQR 23.7–29.3]). Short-term major or life-threatening bleeding were significantly higher in CD patients (odds ratio [95% confidential interval]: 3.67 [1.50–8.96], p 0.005). In contrast, no differences were found regarding rates of vascular complications requiring intervention (OR [95% CI]: 1.35 [0.31–5.90], p=0.662), permanent pacemaker implantation (OR [95% CI]: 0.87 [0.25–2.98], p=1.000) or stroke (OR [95% CI]: 1.51 [0.20–11.64], p=0.504). Importantly, dialysis patients had significantly higher rates of in-hospital, 30-day and 1-year mortality rates (13.6 vs 2.1%, p&lt;0.001; 18.9% vs 2.9, p&lt;0.001 and 26.4% vs 10.7%, p&lt;0.001, respectively). On multivariate analysis, after adjusting for age, gender, relevant co-morbidities, and procedure-related complications, CD remained independently associated with mortality at 1-year. Survival curves during follow up are presented in Figure 1.

Conclusions

Chronic dialysis patients submitted to TAVI had significantly higher rates of short-term life threatening and/or major bleeding, short-term and long-term mortality. Careful selection of patients who would benefit from TAVI among patients with ERDS requiring dialysis is necessary to prevent high rates of postprocedural complications and improve outcomes of this high-risk population.

Funding Acknowledgement

Type of funding sources: None.

A preliminary analysis regarding functional mitral regurgitation grading with echocardiography and CMR: in search of similarities and resolving discordances

Background

Functional mitral regurgitation (fMR) severity grading by 2D transthoracic echocardiography (TTE) can be a complex task, especially in patients where PISA assumptions are not met (eg. non-circular orifice or multiple jets). Cardiac magnetic resonance (CMR) can provide further insight on the hemodynamic burden of fMR by accurately determining mitral regurgitant fraction (RegFrac). Our goal was to investigate the concordance and disagreement between the two modalities in assessing fMR.

Methodology

Single-center prospective study of fMR patients performing same-day TTE and CMR from Feb to Dec 2021. MR severity was classified according to 2020 ACC consensus: grade I (mild; EROA &lt;0.20 cm2), grade II (moderate; EROA 0.20–0.29 cm2), grade III (moderate-to-severe; EROA 0.30–0.39 cm2) and grade IV (severe; EROA ≥0.40 cm2). MR assessment by CMR was determined through regurgitant volume (RVol) and RegFrac quantification. A RegFrac ≥35% (recently shown as the best cut-off for prognostication) was considered hemodynamically significant.

Results

A total of 36 patients were included (age 65±14y; 74% male; left ventricle [LV] ejection fraction by TTE and CMR 35±13% and 34±11%, respectively). Mean RVol and EROA by TTE were 28±11mL and 0.18±0.8 cm2. Mean RVol and Regfrac by CMR were 20±13 mL and 25±12%, respectively. A moderate correlation between RVol by TTE and CMR was found (Pearson's R 0.58, p=0.001). According to TTE, there were 20 patients (56%) with grade I fMR, 12 patients (33%) with grade II fMR and 4 patients (11%) with grade III fMR. All patients considered to have mild (grade I) fMR by TTE had a RegFrac &lt;35% at CMR. However, amongst those with moderate and moderate-to-severe (grades II and III) fMR, there were 8 patients (50%) with hemodynamic significant fMR (RegFrac ≥35%) at CMR – see Figure 1. Those with RegFrac ≥35% by CMR had higher indexed LV diastolic (165±24 vs 139±48 mL/m2) and systolic (116±31 vs 95±48 mL/m2) volumes and higher pulmonary artery systolic pressures (48±14 vs 41±16 mmHg) when compared with patients whose RegFrac was &lt;35%, even though statistically significance was not reached.

Conclusion

Using the criterion of RegFrac ≥35%, CMR re-classifies (half for each side) the patients with moderate and moderate-to-severe regurgitations by TTE. Recognizing, overcoming and resolving the disagreements between the techniques is the way forward to reach excellence.

Funding Acknowledgement

Type of funding sources: None.

Use of 2D and co-culture cell models to assess the toxicity of zein nanoparticles loading insect repellents icaridin and geraniol

After the latest dengue and Zika outbreaks, the fight against mosquito vectors has become an emerging area of research. One tool for this combat is repellents; however, these products are composed of different toxic agents. Botanical compounds with repellent potential are an alternative; however these compounds are highly volatile. Thus, the present study aimed to synthesize zein-based polymeric nanoparticles as an efficient carrier system for the sustained release of the repellents icaridin and geraniol and evaluate the toxicity of these nanorepellents comparing two different cell models. In vitro tests were carried out due to current Brazilian legislation prohibiting animal testing for cosmetics (current classification of repellents). The cytotoxicity and genotoxicity of the nanoparticles were evaluated in 2D and co-culture cell models (A549/lung epithelium, HaCaT/keratinocytes, HT-29/intestinal epithelium, and THP-1/peripheral blood monocytes). Cell viability by mitochondrial activity, cell membrane integrity, damage to genetic material, and expression of genes involved in the allergic/inflammatory system were evaluated. The results of cytotoxicity evaluation showed cell viability above 70% in both cell models. No differences were observed in genotoxicity assessment between cells exposed to nanorepellents and controls. In contrast, gene expression analysis showed increased cytokine expression for the emulsion compounds in 2D cell cultures compared to co-cultures. These findings open perspectives that zein-based nanorepellents have potential applications due to the reduced toxicity observed when the compounds are encapsulated and emerge as an alternative for arbovirus control. In addition, the study demonstrated that depending on the analysis, different results might be observed when comparing 2D and co-culture cell models to evaluate the toxicity of new nanosystems.

Women in Neurosurgery: Historical Path to Self-Segregation and Proposal for an Integrated Future

Despite the rising percentage of women accessing the medical profession over the last few decades, surgical specialties are still largely male-dominated; in particular, a remarkable gender disparity is evident in neurosurgery, where only 19% of practitioners are females. Although women may be reluctant to choose a challenging specialty like neurosurgery due to concerns around how to balance family and career, it must be admitted that prejudices against female neurosurgeons have been deeply rooted for long, prompting many to give up and switch track to less demanding subspecialties. Among those who have persisted, many, if not most, have experienced difficulties in career progression and received unequal treatment in comparison with their male counterparts. In 1989, a group of 8 female neurosurgeons founded Women in Neurosurgery (WINS), an organization that aimed to guarantee inclusivity in neurosurgery, encouraging a better and more egalitarian working environment. Thereafter, WINS sessions were regularly promoted at international conferences, offering female neurosurgeons a platform to report issues related to gender discrimination. Over recent years, the mission of WINS sessions in national and international conferences has taken an unexpected deviation; they have progressively become supplementary scientific sessions with only women neurosurgeons as speakers, thus paving the road to a form of self-segregation. This tendency has also resulted in the establishment of sections of only female neurosurgeons within some national societies. Although there remains a faction that fiercely supports the WINS mindset of reserved spaces for women, such segregation is an upsetting prospect for those who believe that science and professionalism have no gender; a growing part of the global neurosurgical community believes that the conception of a “female neurosurgery” and a “male neurosurgery” is misguided and counterproductive and consider the existence of the WINS as anachronistic and no longer necessary.

Obtainment of Macrophages from Human Monocytes to Assess Leishmania braziliensis Infection Rate and Innate Host Immune Response

Macrophages are multifunctional cells essential to the immune system function, and the primary host cell in Leishmania braziliensis (Lb) infection. These cells are specialized in microorganism recognition and phagocytosis, but also activate other immune cells and present antigens, as well as promote inflammation and tissue repair. Here, we describe a protocol to obtain mononuclear cells from peripheral blood (PBMC) of healthy donors to separate monocytes that then differentiate into macrophages. These cells can then be infected in vitro at different Lb concentrations to evaluate the ability to control infection, as well as evaluate host cell immune response, which can be measured by several methods. PBMCs were first isolated by centrifuging with Ficoll-Hypaque gradient and then plated to allow monocytes to adhere to culture plates; non-adherent cells were removed by washing. Next, adherent cells were cultured with macrophage-colony stimulating factor (M-CSF) for 7 days to induce macrophage differentiation. We suggest plating 2 x 10⁶ cells per well on 24-well plates in order to obtain 2 x 10⁵ macrophages. Fully differentiated macrophages can then be infected with Lb for 4 or 24 hours. This protocol results in a significant percentage of infected cells, which can be assessed by optical or fluorescence microscopy. In addition to infection index, parasite load can be measured by counting the numbers of parasites inside each cell. Further molecular and functional assays can also be performed in culture supernatants or within the macrophages themselves, which allows this protocol to be applied in a variety of contexts and also adapted to other intracellular parasite species.

Predictive factors of non-adherence to asthma medication in pregnancy

Summary

Background. Adherence to asthma medications is a significant problem among pregnant women. Objective. To evaluate asthma medication adherence in pregnant women and to determine the factors that may predict non-adherence in a real-life setting. Methods. A cross-sectional study was performed with pregnant women with asthma followed in a specialized asthma consultation at the Pulmonology Department, between 2014 and 2019. Sociodemographic and clinical variables were collected. Structured telephone interviews were conducted to determine regular medication use during pregnancy. Multiple logistic regression was used to identify predictive factors of asthma medication non-adherence (cessation or dose reduction). Results. A total of 82 pregnant women were included: mean age of 31.3 ± 6.5 years, non-adherence was detected in 29% (n = 24). Multivariable logistic regression analysis revealed that mild asthma during pregnancy (OR, 4.8; 95% CI 1.4-17.1, p = 0.015) and single, separated or divorced mothers (OR, 4.0; 95% CI 1.3-11.8, p = 0.014) were independent predictors of poor adherence to asthma medications. Conclusions. Asthma severity and marital status can strongly predict the asthma medication non-adherence in pregnant females. These findings may help improve asthma education strategies to promote.

A microparticle blood analogue suspension matching blood rheology

The handling of blood in vitro is demanding because of ethical, economical and safety issues. Although several Newtonian and non-Newtonian blood analogues are found in the literature, few studies have used particles to mimic red blood cells (RBCs) and built an analogue with similar rheological properties of blood. This work reports the development of a blood analogue suspension composed of polydimethylsiloxane (PDMS) microparticles with an average diameter of ∼7 μm. High throughput production of PDMS particles is possible using a multi-stage membrane emulsification process; up to ∼6 mL of microparticles are manufactured in 3 hours. PDMS particles at a concentration of around 21% (w/w) at 20 °C present steady, oscillatory and extensional rheologies very similar to those of blood under physiological conditions (37 °C and ∼41% hematocrit), making them a good candidate whole blood analogue. Also, flow studies were performed in microchannels with contraction to study the cell-free layer (CFL) formation and particle deformation, achieving good qualitative results. Using the procedure developed, it is possible to obtain blood analogue fluids with a shelf life of at least 6 months.

Carnival in Brazil as production of health care: narratives from a samba school community

Introduction

Carnival is a popular festival that was introduced in Brazil from the European heritage. However, it was the enslaved African people who saw forms and processes of resistance for the construction of identity during this festive period. The reframing and resistance that blacks establish with carnival is the result of a cultural need to stay alive both as a subject and as a collective. This is how samba schools emerge in the urban peripheries of Rio de Janeiro as a form of artistic, cultural and leisure production. Associations acquire for themselves the role of the State in providing access to rights that many are denied, neglected or scrapped. In these schools, it is possible to observe a relationship of belonging and donation (”principle of gift”) on the part of their so-called community, they are passions and meanings that produce relationships of self-care reaffirmation of intersubjectivity.

Objective

This work aims to identify the carnival as a space for the production of projects, resistances and protagonisms and to analyze the meanings of the subjective processes of health, disease, care and carnival, through the narratives of a samba school community.

Methodology

This is an exploratory analysis of a qualitative approach in public health. A samba school was chosen from the special group of the capixaba carnival, which is located in a peripheral region. We will use it to define snowball technical sampling. The data will be collected through semi-structured interviews and on-site observations by the researcher. The data analysis methodology used will be discourse analysis.

Expected Results

It is expected to understand the different practices and processes of health, disease, care and carnival, among a peripheral community that is part of a samba school.

Key messages

This work aims to analyze health care about a cultural aspect of marginalized populations and how health policies are related to carnival. Impact on the production of knowledge about popular culture and health.

Care for women in a situation of violence: an institutionalist look

Objective

To know the dynamic processes that involve the production of care for women in situations of violence.

Methods

Study of qualitative approach and cartographic inspiration based on the theoretical reference of Institutionalism that had as scenario a reference center for women in domestic violence located in Espírito Santo, Brazil. Six professionals who worked directly in the care of women participated in the research. Interventions were carried out, through seven workshops, using storytelling. The material production tools were narratives, the researcher's field diary and the collective field diary, which was built from the record and observation of all the participants in the study. The workshops were held at the center according to the availability of participants and lasted an average of 60 minutes. The meetings were recorded and later transcribed together with the notes of the field diaries, seeking, through a cartography, to give meaning to the experiences lived by the participants. Through the analysis of implication, it was possible to give visibility to the various relationships that constitute a certain reality, in which the researcher is involved.

Results

The study pointed out that violence crosses all women influencing the production of care offered by professionals at the reference center. The narratives multiplied senses contributing to the problematization of the care offered, providing the qualification of other ways of thinking/acting in health.

Conclusions

From an ethical-aesthetic-political paradigm it is possible to produce reflections that broaden the view of care for women in violent situations beyond biological issues, contributing with desirable productive processes in the prevention of violence and the promotion of health.

Key messages

It gives visibility to micropolitical processes and contributes to the construction of policies for women's health capable of welcoming differences and singularities. It shows innovation for the field of qualitative health research, broadening the view on the care of women in situations of violence beyond biological issues.

The access to complementary and integrative health practices in public health system in Brazil

Background

A qualitative and exploratory study that analyzed the perspective of access to Integrative and Complementary Practices in Health (PICS) by listening users from a selected service of primary care of a municipality.

Objective

Analyze the access to PICS in a health public service of a municipality in a state of Brazil, from the perspective of users, as well as aimed at understand the needs and desires of health care these users in the search process and use of PICS, identifying facilitators and barriers in this trajectory.

Methods

The theoretical reference from Frenk on access was used, which systematizes the flow of events at the moment when the health need is perceived until the effectiveness of the care, besides the demand and entrance in the health services and the continuity of the treatment. The data collection was done by participant observation and semi-structured interview with 29 users of the service. The narratives were worked through the analysis of thematic content.

Results

The results indicated two groups of PICS: complex medical systems and therapeutic resources. There were differences in the organization of the offer with consequent influence on the different forms of access. It was registered the interest for the use of health care in a non-biomedical logic and a re-signification of the health-disease process in PICS users, contributing to the continuity of health production.

Conclusions

It was concluded that the current models of access analysis do not contemplate the diversities of access to the PICS, and the various possibilities of encounters with these practices allow the identification of the marginality of this care in all cases analyzed.

Key messages

Integrative and Complementary Health Practices gain national relevance as they contribute to the development of health promoting activities, focus on the individual, prevention and comprehensive care. However, considered a controversial topic in a hegemonically biomedical scenario, the incorporation of these new knowledge and practices in the health field occurs in a marginal way.

P724 The mysteries of sinus of Valsalva

Sinus of Valsalva aneurysms are a rare pathology that can be clinically silent during years and/or become suddenly symptomatic. We described 3 cases with different clinical presentation, complications and surgical treatment.

A 26-year-old male, competitive cyclist was admitted with a 1.5 month history of fatigue, palpitations, and nocturnal cough and sweating. At physical examination he was apyretic, blood pressure 157/49mmHg and radial pulse 96 bpm; jugular vein engorgement and continuous heart murmur, were noticed. Blood samples only revealed a mild raised BNP. EKG showed sinus tachycardia and right intraventricular conduction delay and the transthoracic echocardiography (TTE) revealed high velocity systolic-diastolic shunt (image) between a non-dilated right coronary sinus (RCS) and the right atrium (RA); moderate left ventricle dilation, severe right atrium and mild right ventricle enlargement with mild pulmonary hypertension and normal biventricular systolic function. He was referred to angioCT that showed a large communication between a non-dilated RCS and RA with signs of right ventricular overload. He was submitted to surgery, where ruptured aneurysm sac was found. Fistula closure, aneurysm sac suture and tricuspid annuloplasty were performed.

A 45-year-old male asymptomatic, with no relevant medical background went to a Cardiology consultation after detection of a holossistolic murmur in the physical exam. EKG showed sinus rhythm arrhythmia with a nonspecific intraventricular conduction delay and the TTE revealed a communication between a dilated noncoronary sinus (NCS) and RA; the biventricular systolic function was normal. He was referred to angioCT which confirmed the diagnosis. He was submitted to surgery where an exeresis and closure of the fistula was performed.

A 38-year-old male with no relevant medical background was admitted to emergence room for an intermittent anterior thoracic pain radiating to the neck (2 days of evolution). The EKG showed sinus tachycardia, incomplete right bundle branch block and the high-sensitivity troponin assays were negative. The TTE revealed severe sinus of Valsalva aneurysm, particularly of the NCS with mild aortic regurgitation. The patient performed transesophageal echocardiography and angioCT which excluded an acute aortic syndrome. He was oriented to surgery where a contained rupture of the RCS and a non-visualization of the ostium right coronary artery were detected, suggesting an intimal dissection. The patient was submitted to Bentall procedure and a bypass with internal mammary artery to right coronary artery.

In spite of the unclear etiology, all the cases had a good clinical and echocardiographic evolution at follow-up. The difficulty in making a timely diagnosis is related to the variability of clinical presentation and the need of high clinical suspicion. Echocardiography and angioTC have demonstrated its value, in providing a prompt diagnosis and appropriate management guidance.

Abstract P724 Figure. Ruptured aneurysm sac and fistula

Molecular Aspects of Dendritic Cell Activation in Leishmaniasis: An Immunobiological View

Dendritic cells (DC) are a diverse group of leukocytes responsible for bridging innate and adaptive immunity. Despite their functional versatility, DCs exist primarily in two basic functional states: immature and mature. A large body of evidence suggests that upon interactions with pathogens, DCs undergo intricate cellular processes that culminate in their activation, which is paramount to the orchestration of effective immune responses against Leishmania parasites. Herein we offer a concise review of the emerging hallmarks of DCs activation in leishmaniasis as well as a comprehensive discussion of the following underlying molecular events: DC-Leishmania interaction, antigen uptake, costimulatory molecule expression, parasite ability to affect DC migration, antigen presentation, metabolic reprogramming, and epigenetic alterations.

Study of worker's exposure to Tantalum-bearing particles in a mining and metallurgical plant

The objective of this study was to assess worker exposure to mineral dust particles, and a metabolic model, based on the model adopted by ICRP, was applied to assess human exposure to Ta, and predicted values of Ta concentrations in excreta. The occupational exposure to Th, U, Nb, and Ta-bearing particles during routine tasks to obtain Fe-Nb alloys was estimated using air samplers and excreta samples. Ta concentrations in food samples and in drinking water were also determined. The results support that workers were occupationally exposed to Ta-bearing particles, and also indicate that a source of Ta exposure for both workers and the control group was the ingestion of drinking water containing soluble compounds of Ta. Therefore, some Ta compounds should be considered soluble compounds in gastrointestinal tract. Consequently, the metabolic model based on ICRP metabolic model and/or the transfer factor f ₁ for Ta should be reviewed and the solubility of Ta compounds in gastrointestinal should be determined.

Reference equations for the 6-minute walk distance in healthy Portuguese subjects 18-70 years old

INTRODUCTION

Six-minute walk test (6MWT) is used for evaluating functional exercise capacity. To the best of our knowledge, there are no reference equations to predict six-minute walk distance (6MWD) for the Portuguese population. The aims of the present study were to measure anthropometric data and 6MWD in a sample of healthy Portuguese population, to establish reference equations to predict 6MWD and to compare our equations with those obtained by previously published studies.

METHODS

We conducted an observational prospective study. We consecutively recruited 158 healthy 18-70 years old subjects from Porto district, who performed two 6MWTs using a standardized protocol. The best 6MWD was used for further analysis.

RESULTS

The mean 6MWD was 627.8m (SD=73.3m). The variables that were significantly associated with the 6MWD were age, sex, BMI and ΔHR (Heart Rate_{at the end of the test}-HR_{at rest)}. We found three explanatory models for 6MWD, the best with an explanatory power of 38%: 6MWD=721.7-1.6×Age-4.0×BMI+0.9×ΔHR+58.4×Sex. We verified that 6MWD decreased 1.6m per year of age, and 4.0m per unit of BMI and increased 0.892m per beat per minute. Moreover, on average, males walk 58.4m more than females (p<0.001). Applying equations from other studies to our population resulted in an overestimation or underestimation of the 6MWD.

CONCLUSION

The present study was the first to describe the 6MWD in healthy Portuguese people aged 18-70 years old and to propose predictive equations. These can contribute to improving the evaluation of Caucasian Mediterranean patients with diseases that affect their functional capacity.

Salmonella Typhi Colonization Provokes Extensive Transcriptional Changes Aimed at Evading Host Mucosal Immune Defense During Early Infection of Human Intestinal Tissue

Commensal microorganisms influence a variety of host functions in the gut, including immune response, glucose homeostasis, metabolic pathways and oxidative stress, among others. This study describes how Salmonella Typhi, the pathogen responsible for typhoid fever, uses similar strategies to escape immune defense responses and survive within its human host. To elucidate the early mechanisms of typhoid fever, we performed studies using healthy human intestinal tissue samples and "mini-guts," organoids grown from intestinal tissue taken from biopsy specimens. We analyzed gene expression changes in human intestinal specimens and bacterial cells both separately and after colonization. Our results showed mechanistic strategies that S. Typhi uses to rearrange the cellular machinery of the host cytoskeleton to successfully invade the intestinal epithelium, promote polarized cytokine release and evade immune system activation by downregulating genes involved in antigen sampling and presentation during infection. This work adds novel information regarding S. Typhi infection pathogenesis in humans, by replicating work shown in traditional cell models, and providing new data that can be applied to future vaccine development strategies.

Role of the impulse oscillometry in the evaluation of tracheal stenosis

INTRODUCTION AND OBJECTIVES

Tracheal stenosis is a rare and challenging disease. Bronchoscopy is the gold standard for diagnosis and assessment but brings inherent risks. Spirometry is commonly used to access obstructions but is not always feasible due to patient related factors. We therefore considered impulse oscillometry (IOS) as a non-invasive method to quantify airway obstruction and its potential use for diagnosis and follow-up of tracheal stenosis.

MATERIALS AND METHODS

Patients with confirmed tracheal stenosis were recruited between January 1st, 2015 and December 31st, 2016. Before bronchoscopy, all subjects underwent IOS and spirometry; for patients submitted to interventional bronchoscopy the same techniques were also performed after the procedure. We assessed the correlation between IOS measurements and airway narrowing as well as between IOS and spirometry values.

RESULTS

Twenty-one patients were included. Tracheal narrowing was inversely correlated with X5% (r -0.442, p 0.045) and positively correlated with FEV1/PEF (r 0.467, p 0.033). The stenosis length was inversely correlated with PEF and PEF% (r -0.729, p=0.001 and r -0.707, p=0.002, respectively). There was a strong correlation between spirometric and IOS values. We did not find any significant differences between pre- and post-intervention IOS values for patients assessed after interventional bronchoscopy.

CONCLUSIONS

Our study showed a weak correlation between X5% and tracheal narrowing making it unclear whether IOS can be used for physiological assessment of patients with tracheal stenosis. Stenosis length correlated with PEF making it a potential predictor of successful surgical approach. The correlation between IOS and spirometric values makes IOS a potential alternative in patients with suspected tracheal stenosis who are not able to perform spirometry. Larger scale studies should clarify the role of IOS in this pathology.

Severe asthma in obese patients: Improvement of lung function after treatment with omalizumab

INTRODUCTION

Asthma and obesity have a considerable impact on public health and their prevalence is increasing. Obesity is a known risk factor for asthma and can make it more difficult to control. Omalizumab is recommended in patients with severe allergic persistent asthma. The aim of this study was to assess the impact of omalizumab treatment in obese asthmatic patients with poorly controlled severe persistent asthma.

METHODOLOGY

A non-interventional, prospective study was conducted, in an outpatient asthma clinic. All patients with severe asthma who started treatment with omalizumab were included and followed over 12 months. The study population was divided into two groups (obese and non-obese) for statistical analysis (descriptive and comparative analysis).

RESULTS

Thirty-two patients (19 obese) were followed. After 12 months of omalizumab treatment, there was a statistically significant improvement in body mass index, number of exacerbations in the previous year, rescue medication, disease control and lung function, in the whole population. At the end of the study obese patients had a significantly better lung function (FEV₁) than non-obese.

DISCUSSION

As described in the literature, there was a significant reduction in the number of exacerbations in the previous year, rescue medication and better disease control, in the whole population. In relation to lung function, about which published data are inconsistent, treatment with omalizumab significantly improved it in obese patients.

CONCLUSION

Our study showed that omalizumab significantly improved asthma control, reduced rescue medication and asthma exacerbations in all the population; and for the first time showed that obese patients achieved significantly improved lung function.

Does any association exist between Chronic Obstructive Pulmonary Disease and Erectile Dysfunction? The DECODED study

INTRODUCTION

Erectile dysfunction (ED) is the inability to achieve or maintain an erection for satisfactory sexual activity. Recent studies have shown an association between ED and chronic obstructive pulmonary disease (COPD). However, this issue is often ignored. We aimed to evaluate the ED prevalence in COPD patients and its risk factors and to study the impact of dyspnea in sexual activity.

METHODS

Cross-sectional study that included sexually active male patients with COPD. The International Index of Erectile Function (IIEF-5) questionnaire evaluated ED and the Respiratory Experiences with Sexuality Profile (RESP) was used to evaluate the impact of dyspnea on sexual activity. Risk factors for mild-moderate or moderate ED were determined using logistic regression.

RESULTS

84 patients were consecutively assessed for eligibility, 67 were included (median age: 65 years, 13% never-smokers). Twenty two percent had COPD 2011-GOLD A; 22% GOLD B, 14% GOLD C and 42% GOLD D. Fifty-eight patients (87%) had some degree of ED: 26 (45%) mild, 20 (34%) mild-moderate and 12 (21%) moderate ED. ED occurred in all GOLD stages of COPD, mainly in GOLD B and D stages. Higher CAT score was independently associated to mild-moderate/moderate ED. Most patients (85%) reported dyspnea during their sexual activity but 72% had never talked about it with their physician.

CONCLUSIONS

ED is highly prevalent among COPD patients and it is more severe in patients with higher CAT scores. Dyspnea affects their sexual activity but this is not a topic often discussed between patients and doctors, something which needs to be improved.

Blood cell responses and metallothionein in the liver, kidney and muscles of bullfrog tadpoles, Lithobates catesbeianus, following exposure to different metals

The hematological parameters and metallothionein (MT) levels in the liver, kidney and muscles were measured in bullfrog tadpoles, Lithobates catesbeianus, following exposures to 1 μg L^-1 of zinc (Zn), copper (Cu) and cadmium (Cd) alone or in combination (1:1 and 1:1:1) for 2 and 16 days. Metal accumulation occurred in all organs, with the highest values found in the kidney, followed by the muscles and liver. After exposure to isolated metals, the accumulation was in the following order: Cd > Zn > Cu in the liver and muscles and Cd > Cu > Zn in the kidney. Exposure to combined metals (Zn + Cu, Zn + Cd, Cu + Cd and Zn + Cu + Cd) revealed complex responses, such as metal accumulation increased or decreased over the exposure periods, suggesting possible competion at the uptake sites and/or metabolization and elimination processes in each organ. The MT concentration increased in the organs of tadpoles following metal exposure alone, mainly in the liver, for both periods. After the combined exposures, the MT levels were higher in the liver and muscles at 16 days, suggesting that the interaction between metals was additive, and the level was decreased in the kidney after 2 and 16 days of exposure. The whole blood hemoglobin content (Hb), red blood cell count (RBCs) and mean corpuscular hemoglobin (MCH) differed from the control groups after 2 and 16 days of exposure, showing changes in the improvement of oxygen transport. The number of lymphocytes increased, and the levels of neutrophils, eosinophils, basophils and monocytes were reduced after exposure to the metals. The changes in blood cells suggested that tadpoles have a mechanism to improve oxygen transport probably because of the increased oxygen demand and a general reduction in defense cells. The exposure of L. catesbeianus to metals during the larval phase can generate long-term dysfunction to a degree, which could lead to alterations in their health status.

Generation of micro-sized PDMS particles by a flow focusing technique for biomicrofluidics applications

Polydimethylsiloxane (PDMS), due to its remarkable properties, is one of the most widely used polymers in many industrial and medical applications. In this work, a technique based on a flow focusing technique is used to produce PDMS spherical particles with sizes of a few microns. PDMS precursor is injected through a hypodermic needle to form a film/reservoir over the needle's outer surface. This film flows towards the needle tip until a liquid ligament is steadily ejected thanks to the action of a coflowing viscous liquid stream. The outcome is a capillary jet which breaks up into PDMS precursor droplets due to the growth of capillary waves producing a micrometer emulsion. The PDMS liquid droplets in the solution are thermally cured into solid microparticles. The size distribution of the particles is analyzed before and after curing, showing an acceptable degree of monodispersity. The PDMS liquid droplets suffer shrinkage while curing. These microparticles can be used in very varied technological fields, such as biomedicine, biotechnology, pharmacy, and industrial engineering.

Alpha-1 antitrypsin deficiency caused by a novel mutation (p.Leu263Pro): Pi*ZQ0gaia - Q0gaia allele

Severe alpha-1 antitrypsin deficiency (AATD) is generally associated with PI*ZZ genotype and less often with combinations of PI*Z, PI*S, and other rarer deficiency or null (Q0) alleles. Severe AATD predisposes patients to various diseases, including pulmonary emphysema. Presented here is a case report of a young man with COPD and AATD. The investigation of the AATD showed a novel mutation p.Leu263Pro (c.860T>C), which was named Q0gaia (Pi*ZQ0gaia). Q0gaia is associated with very low or no detectable serum concentrations of AAT.

Biomarker Evaluation in Fish After Prolonged Exposure to Nano-TiO2: Influence of Illumination Conditions and Crystal Phase

In this study, we evaluated the effects of prolonged exposure to two different nano-TiO2 crystal phases under different illumination conditions. Fish (Piaractus mesopotamicus) were exposed for 21 days to 100 mg/L of nano-TiO2 anatase and a mixture of anatase:rutile (80%:20%) under visible light and UV light (UVA and B, 22.47 J/cm2/h). The following oxidative stress biomarkers were mon- itored: concentrations of lipid hydroperoxide (LPO), carbonylated proteins (PCO), and specific activ- ities of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST). Other biomarkers as well as specific activities of acid phosphatase (AP), Na+, K(+)-ATPase and metalloth- ionein levels (MT) were also evaluated. Moreover, micronucleus and comet assays were performed to assess genotoxicity. Our results showed low toxicity of nano-TiO2 to fish and lack of titanium accumulation in muscle tissue. However, it was observed the occurrence of sublethal effects that were influenced by nano-TiO2 crystal phase and illumination condition. Pure anatase caused more oxidative damage without co-exposure to UV, while the mixture anatase:rutile caused more sub- lethal effects when exposure occurred under UV. These findings show that the specific activity of CAT, GST, PCO levels and comet assay are useful as biomarkers of prolonged exposure to nano- TiO2. Overall, our study substantiates the development and implementation of nanoecotoxicological protocols.

Ecotoxicological evaluation of poly(epsilon-caprolactone) nanocapsules containing triazine herbicides

The triazine class of herbicides includes the compounds ametryn, atrazine, and simazine, which are used to control weeds in plantations of crops such as maize, sorghum, and sugar cane. Despite their acceptance in agriculture, these herbicides can be dangerous to the environment, depending on their toxicity, the degree of contamination, and the duration of exposure. Controlled release systems are increasingly used to mitigate problems of toxicity and minimize environmental impacts, and can also increase herbicide efficiency. The objective of this work was to prepare poly(epsilon-caprolactone) nanocapsules containing ametryn and atrazine, and evaluate their toxicity to aquatic organisms as well as in cytogenetic tests employing human lymphocyte cultures. The PCL nanocapsules were prepared according to the interfacial deposition of pre-formed polymer method. Ecotoxicological assays were performed with the alga Pseudokirchneriella subcapitata and the microcrustacean Daphnia similis. The cytogenetic tests consisted of observing mitotic index alterations after exposing lymphocyte cell cultures to different formulations. Encapsulation of the herbicides in the nanocapsules resulted in lower toxicity to the alga and higher toxicity to the microcrustacean, compared to the herbicides alone. The cytogenetic tests showed that formulations of nanocapsules containing the herbicides were less toxic than the herbicides alone. The findings indicate the potential of the nanocapsule formulations in agricultural applications, where they could help to reduce the quantities of herbicides used as well as impacts on the environment and human health.

Fish exposure to nano-TiO2 under different experimental conditions: methodological aspects for nanoecotoxicology investigations

The ecotoxicology of nano-TiO2 has been extensively studied in recent years; however, few toxicological investigations have considered the photocatalytic properties of the substance, which can increase its toxicity to aquatic biota. The aim of this work was to evaluate the effects on fish exposed to different nano-TiO2 concentrations and illumination conditions. The interaction of these variables was investigated by observing the survival of the organisms, together with biomarkers of biochemical and genetic alterations. Fish (Piaractus mesopotamicus) were exposed for 96 h to 0, 1, 10, and 100 mg/L of nano-TiO2, under visible light, and visible light with ultraviolet (UV) light (22.47 J/cm(2)/h). The following biomarkers of oxidative stress were monitored in the liver: concentrations of lipid hydroperoxide and carbonylated protein, and specific activities of superoxide dismutase, catalase, and glutathione S-transferase. Other biomarkers of physiological function were also studied: the specific activities of acid phosphatase and Na,K-ATPase were analyzed in the liver and brain, respectively, and the concentration of metallothionein was measured in the gills. In addition, micronucleus and comet assays were performed with blood as genotoxic biomarkers. Nano-TiO2 caused no mortality under any of the conditions tested, but induced sublethal effects that were influenced by illumination condition. Under both illumination conditions tested, exposure to 100 mg/L showed an inhibition of acid phosphatase activity. Under visible light, there was an increase in metallothionein level in fish exposed to 1 mg/L of nano-TiO2. Under UV light, protein carbonylation was reduced in groups exposed to 1 and 10 mg/L, while nucleus alterations in erythrocytes were higher in fish exposed to 10 mg/L. As well as improving the understanding of nano-TiO2 toxicity, the findings demonstrated the importance of considering the experimental conditions in nanoecotoxicological tests. This work provides information for the development of protocols to study substances whose toxicity is affected by illumination conditions.

Human red blood cell behavior under homogeneous extensional flow in a hyperbolic-shaped microchannel

It is well known that certain pathological conditions result in a decrease of red blood cells (RBCs) deformability and subsequently can significantly alter the blood flow in microcirculation, which may block capillaries and cause ischemia in the tissues. Microfluidic systems able to obtain reliable quantitative measurements of RBC deformability hold the key to understand and diagnose RBC related diseases. In this work, a microfluidic system composed of a microchannel with a hyperbolic-shaped contraction followed by a sudden expansion is presented. We provide a detailed quantitative description of the degree of deformation of human RBCs under a controlled homogeneous extensional flow field. We measured the deformation index (DI) as well as the velocity of the RBCs travelling along the centerline of the channel for four different flow rates and analyze the impact of the particle Reynolds number. The results show that human RBC deformation tends to reach a plateau value in the region of constant extensional rate, the value of which depends on the extension rate. Additionally, we observe that the presence of a sudden expansion downstream of the hyperbolic contraction modifies the spatial distribution of cells and substantially increases the cell free layer (CFL) downstream of the expansion plane similarly to what is seen in other expansion flows. Beyond a certain value of flow rate, there is only a weak effect of inlet flow rates on the enhancement of the downstream CFL. These in vitro experiments show the potential of using microfluidic systems with hyperbolic-shaped microchannels both for the separation of the RBCs from plasma and to assess changes in RBC deformability in physiological and pathological situations for clinical purposes. However, the selection of the geometry and the identification of the most suitable region to evaluate the changes on the RBC deformability under extensional flows are crucial if microfluidics is to be used as an in vitro clinical methodology to detect circulatory diseases.