Exercise-Induced Bronchoconstriction Background Prevalence Around the World.

Exercise-induced bronchoconstriction (EIB), subgrouped as exercise-induced bronchoconstriction with asthma (EIBa) or without asthma, is defined as acute airway narrowing that occurs during or after exercise. EIB has been described mostly in patients with asthma and athletes. Prevalence differs according to the subjects studied, challenge methods, and EIB definition.

Reference equations for DLNO and DLCO in Mexican Hispanics: influence of altitude and race.

Objectives: This study aimed to evaluate pulmonary diffusing capacity for nitric oxide (DLNO) and pulmonary diffusing capacity for carbon monoxide (DLCO) in Mexican Hispanics born and raised at 2240 m altitude (midlanders) compared with those born and raised at sea level (lowlanders). It also aimed to assess the effectiveness of race-specific reference equations for pulmonary diffusing capacity (white people vs Mexican Hispanics) in minimising root mean square errors (RMSE) compared with race-neutral equations.

Methods: DLNO, DLCO, alveolar volume (VA) and gas transfer coefficients (KNO and KCO) were measured in 392 Mexican Hispanics (5 to 78 years) and compared with 1056 white subjects (5 to 95 years).

Reference equations using segmented regressions for impulse oscillometry in healthy subjects aged 2.7-90 years.

Background: Published reference equations for impulse oscillometry (IOS) usually encompass a specific age group but not the entire lifespan. This may lead to discordant predicted values when two or more non-coincident equations can be applied to the same person, or when a person moves from one equation to the next non-convergent equation as he or she gets older. Thus, our aim was to provide a single reference equation for each IOS variable that could be applied from infancy to old age.

Lung function is related to salivary cytokines and hormones in healthy children. An exploratory cross-sectional study.

Pulmonary mechanics has been traditionally viewed as determined by lung size and physical factors such as frictional forces and tissue viscoelastic properties, but few information exists regarding potential influences of cytokines and hormones on lung function. Concentrations of 28 cytokines and hormones were measured in saliva from clinically healthy scholar children, purposely selected to include a wide range of body mass index (BMI). Lung function was assessed by impulse oscillometry, spirometry, and diffusing capacity for carbon monoxide, and expressed as z-score or percent predicted.

[Small airway: from definition to treatment].

The small airway, present since the origins of humanity and described barely a century ago, has recently been discovered as the anatomical site where inflammation begins in some obstructive lung diseases, such as asthma and Chronic Obstructive Pulmonary Disease (COPD), per se. Small airway dysfuction was identified in up to 91% of asthmatic patients and in a large proportion of COPD patients. In subjects without pathology, small airway represent 98.

Maximal inspiratory and expiratory flow at moderate altitude: a study of a Latin American population.

Background: Peak inspiratory and expiratory flows (PIF, PEF) are parameters used to evaluate the mechanics of the respiratory system. These parameters can vary based on whether they are measured using mechanical devices vs. spirometry and based on the barometric pressure at which the measurements are obtained.

Offline exhaled nitric oxide in children: chemiluminescence vs. electrochemical devices.

Background: Exhaled nitric oxide (eNO) is a noninvasive marker of airway inflammation that has been used in children, using the "offline" technique. To the extent of our knowledge, no article reported in literature compares the concordance and correlation between the two different technologies used to measure eNO at tidal volume offline. This study aimed to report the concordance and correlation of the eNO measured "offline" at tidal volume, using chemioluminiscence (cl) vs electrochemical devices (eq).

Gas Exchange Impairment During COVID-19 Recovery.

Background: Persistent impairment of pulmonary function and exercise capacity has been known to last for months or even years in the survivors who recovered from other coronavirus pneumonia. Some reports showed that subjects with coronavirus disease 2019 pneumonia after being discharged could have several sequelae, but there are few studies on gas exchange and exercise capacity complications in these subjects.

Aims: To describe residual gas exchange abnormalities during recovery from coronavirus disease 2019 pneumonia.

Salivary concentrations of cytokines and other analytes in healthy children.

Background: Blood has been the usual biological fluid for measuring analytes, but there is mounting evidence that saliva may be also useful for detecting cytokines in a noninvasive way. Thus, in this study we aimed to determine concentration of cytokines and other analytes in saliva from a population of healthy children.

Methods: We collected un-stimulated whole saliva samples from clinically healthy children, and concentration of 17 cytokines and 12 other analytes were measured in supernatants.

Functional Respiratory Evaluation in the COVID-19 Era: The Role of Pulmonary Function Test Laboratories.

The pandemic character of coronavirus disease-19 (COVID-19) requires strategy changes designed to guarantee the safety of patients and health-care professionals. We are greatly concerned by the limitations in the operation of pulmonary function test (PFT) laboratories, since there is a high risk of disease progression in patients with chronic pulmonary diseases, and we are now faced by the influx of a new group of individuals in the recovery phase of post-COVID-19-syndrome that requires evaluation and follow-up of their respiratory function. To reestablish the operation of PFT laboratories limiting the risk of cross-contamination, we herein present the consensus reached by a group of experts in respiratory physiology, most of whom work in PFT laboratories in several Latin American countries, on the applicable recommendations for severe acute respiratory syndrome coronavirus 2 pneumonia survivors when undergoing PFT.

Comparing Spirometric Reference Values From Childhood to Old Age Estimated by LMS and Linear Regression Models.

Background: Proper reference values for lung function testing are essential for achieving adequate interpretations. The LMS procedure (lambda, mu, sigma) permits continuous analyses of entire populations avoiding gaps in the transition between childhood and adulthood. It also allows more precise calculations of average values, dispersion, and 5th percentiles, which are usually considered the lower limit of normality.

Shorter corridors can be used for the six-minute walk test in subjects with chronic lung diseases.

Background: The main limitation of the six-minute walk test (6-MWT) is that not all pulmonary function testing facilities have an indoor flat, 30-m-long corridor. Therefore, this study aimed 1) to evaluate the correlation and agreement of the distances walked in 30-m- vs. 15-m-long corridors by subjects with chronic lung diseases (CLD group) and 2) to compare the levels of oxygen saturation (nSpO), blood pressure (BP), heart rate recovery at minute one post-exercise (HRR1), and Borg scale scores for dyspnea and fatigue between the two distances walked.

Mesothelin, Calretinin, and Megakaryocyte Potentiating Factor as Biomarkers of Malignant Pleural Mesothelioma.

Purpose: Malignant pleural mesothelioma (MPM) is a highly lethal cancer caused by exposure to asbestos. Currently, the diagnosis is a challenge, carried out by means of invasive methods of limited sensitivity. This is a case-control study to evaluate the individual and combined performance of minimally invasive biomarkers for the diagnosis of MPM.

Quality of Pulmonary Function Tests in Participants with Down Syndrome.

Introduction: People with Down syndrome (DS) have high respiratory morbidity, evaluating their respiratory health with standardized, objective tests is desirable. Thus, the objective of this study was to evaluate the technical quality of Pulmonary Function Tests (PFTs) to determine which ones are most suitable for this population.

Methods: Participants included children, teenagers and adults with DS, 5 years of age or older (n=302).

Inspiratory Capacity and Vital Capacity of Healthy Subjects 9-81 Years of Age at Moderate-High Altitude.

Background: Measurements of inspiratory capacity (IC) and vital capacity (VC) are used to recognize dynamic hyperinflation, but appropriate reference values are required to achieve accurate clinical interpretations. Altitude above sea level is a potential determining factor for lung volumes, including IC and VC.

Objective: To describe IC and VC for healthy people who live in Mexico City at an altitude of 2,240 m above sea level.

Diffusing Capacity of the Lung for Carbon Monoxide in Mexican/Latino Children. Quality Control and Reference Values.

Rationale: Single-breath diffusing capacity of the lung for carbon monoxide (Dl) values are used to evaluate gas exchange; however, the quality of maneuvers performed by children has not been evaluated, and reference values for young people living at moderate altitudes are not well established.

Objectives: Our objectives were 1) to determine whether Dl maneuvers performed by a pediatric population would meet 2017 European Respiratory Society/American Thoracic Society (ERS/ATS) quality control standards; and 2) to report normal Dl values for Mexican/Latino children and adolescents living at moderate altitudes.

Methods: This study involved healthy young people 4-20 years of age from the metropolitan area of Mexico City (2,240 m above sea level) who were recruited in schools from July 2014 to August 2017.

Macrophage Exposure to Polycyclic Aromatic Hydrocarbons From Wood Smoke Reduces the Ability to Control Growth of .

Use of solid fuels for cooking or home heating has been related to various diseases of the respiratory tract. Woodsmoke contains a mixture of carcinogenic polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds. Inhalation of these materials induces local and systemic changes in the immune system which may impair critical cell defense mechanisms; however, few studies have investigated the early effects that PAH exposures have on immune cells as macrophages.

Biomarkers for Predicting Malignant Pleural Mesothelioma in a Mexican Population.

Diagnosis of malignant pleural mesothelioma (MPM) remains a challenge, especially when resources in pathology are limited. The study aimed to evaluate cost-effective tumor markers to predict the probability of MPM in plasma samples in order to accelerate the diagnostic workup of the tissue of potential cases. We conducted a case-control study stratified by gender, which included 75 incident cases with MPM from three Mexican hospitals and 240 controls frequency-matched by age and year of blood drawing.

Longitudinal Evaluation of Lung Function in Patients With Advanced Non-Small Cell Lung Cancer Treated With Concurrent Chemoradiation Therapy.

Purpose: In lung cancer patients, radiation therapy modifies lung architecture, resulting in functional deterioration, which worsens symptoms and reduces quality of life.

Methods And Materials: A multicenter, prospective, longitudinal study was conducted in a cohort of patients with locally advanced and oligometastatic non-small cell lung cancer treated with concurrent chemoradiation therapy (CCRT). A wide array of pulmonary function tests (forced spirometry, body plethysmography, impulse oscillometry, carbon monoxide diffusing capacity, fraction of exhaled nitric oxide, arterial blood gases, and 6-minute walk test) were used to evaluate lung function at baseline; after radiation therapy; and at 6, 12, 24, and 48 weeks after CCRT.

[Prevalence of sleep symptoms and risk of obstructive sleep apnea in Mexico.].

Objective: To estimate the prevalence of sleep related symptoms (SRS) in Mexico, and their distribution by region, urbanization and gender.

Materials And Methods: Cross-sectional study using a national probabilistic sample among adults over 20 years old. We applied the Berlin questionnaire for sleep apnea risk (OSA) and questions on sleep duration, insomnia and sedative use.

Maximum Voluntary Ventilation in a Population Residing at 2,240 Meters Above Sea Level.

Background: Measured maximum voluntary ventilation (MVV) correlates with maximum ventilatory capacity during exercise. As a shortcut, MVV is often estimated by multiplying measured FEV times 35 or 40, but this index varies with altitude due to reduced air density. The objective was to describe MVV in healthy individuals residing at 2,240 m above sea level and compare it with the reference values customarily employed.

Validating Reference Equations for Impulse Oscillometry in Healthy Mexican Children.

Background: The impulse oscillometry system (IOS) measures the impedance (Z) of the respiratory system, but proper interpretation of its results requires adequate reference values. The objectives of this work were: (1) to validate the reference equations for the IOS published previously by our group and (2) to compare the adjustment of new available reference equations for the IOS from different countries in a sample of healthy children.

Methods: Subjects were healthy 4-15-y-old children from the metropolitan area of Mexico City, who performed an IOS test.

Small airway dysfunction in chronic hypersensitivity pneumonitis.

Background And Objective: Lung biopsies from patients with hypersensitivity pneumonitis (HP) have demonstrated small airway (SA) involvement, but there is no information concerning SA function in HP, and it is unknown whether pharmacological treatment could modify its function. SA function in patients with chronic HP using ultrasonic pneumography (UPG) and impulse oscillometry (IOS) was explored. We also compared initial results with those obtained after 4 weeks of standardized treatment with azathioprine and prednisone.