Arterial Blood Gases in Normal Subjects at 2240 Meters Above Sea Level: Impact of Age, Gender, and Body Mass Index.

Background: The values of arterial blood gases (ABG) change with altitude above sea level; empirical verification is essential because ventilatory acclimatization varies with ethnicity and a population's adaptation.

Objective: The aim of the study was to describe ABG in a healthy population residing at 2,240 meters above sea level, to identify the mean level of alveolar ventilation (PaCO), and to know whether a progressive increase in PaCO occurs with age and the impact of increasing body mass index (BMI).

Methods: We conducted a cross-sectional study in a referral center for respiratory diseases in Mexico City.

Functional impact of sequelae in drug-susceptible and multidrug-resistant tuberculosis.

Evidence on the impact of tuberculosis (TB) treatment on lung function is scarce. The aim of this study was to evaluate post-treatment sequelae in drug-susceptible and drug-resistant-TB (DR-TB) cases in Mexico and Italy. At the end of TB treatment the patients underwent complete clinical assessment, functional evaluation of respiratory mechanics, gas exchange and a 6-minute walking test.

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.

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.

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.

Long-Term Stability of a Portable Carbon Monoxide Single-Breath Diffusing Capacity Instrument.

Background: The 2005 American Thoracic Society/European Respiratory Society guidelines for single-breath diffusing capacity of the lung for carbon monoxide (D) recommend a weekly biological control test and/or D simulator to detect instrument error drift. Very little has been published regarding the results of such a quality assurance program. Our aim was to analyze the long-term stability of a portable D instrument.

[Role of physical, psychological and sexual abuse in functional digestive disorders. A case-controls trial.].

Introduction: Abuse has been considered a significant factor on the development of functional gastrointestinal disorders (FGID), especially for severe and treatment-refractory patients. The aim of our study was to evaluate the presence of all FGID according to Rome II criteria, in a group of women with history of physical, psychological and/or sexual abuse.

Material And Methods: A cross sectional study was performed in 96 women (37 +/- 12 years of age) with history of physical, psychological and/or sexual abuse (cases); and 96 open population women (36 +/- 14 years of age) (controls).

Routine liver biopsy to screen for nonalcoholic fatty liver disease (NAFLD) during cholecystectomy for gallstone disease: is it justified?

Background: Nonalcoholic fatty liver disease (NAFLD) and gallstone disease (GD) share common risk factors. There are no firm recommendations regarding screening of NAFLD in patients at risk. Our aim was to assess the prevalence of and factors associated with NAFLD in a cohort of patients operated for symptomatic GD and evaluate the usefulness of routine liver biopsy.

[Frequency and clinical, biochemical and histological characteristics of nonalcoholic fatty liver disease in patients with gallstone disease].

Background: In 1980, nonalcoholic fatty liver disease (NALFD) was described. It is related to the genesis of gallstones and is considered as a manifestation of the metabolic syndrome. In order to determine the frequency, anatomoclinical characteristics and biochemical and histological alterations in NAFLD, patients underwent cholecystectomy (GD).

[Frequency of NAFLD in a group of patients with metabolic syndrome in Veracruz, Mexico].

Introduction: Nonalcoholic fatty liver disease is a very common disease that is being described principally in obese, diabetic and hiperlipidemic patients without significant alcohol consumption (less than 28 ethanol Units per week). Nowadays it is considered as the hepatic manifestation of the metabolic syndrome. The frequency of Non Alcoholic Sreatohepatic (NASH) is 30 to 35% in general population, but it reaches to 70% in patients whose Body Mass Index (BMI) is above 30 kg/m2 as it occurs with diabetic patients.