Structural and functional changes in the skeletal muscles of COPD patients: the "compartments" theory.

This review focuses on the structural and functional changes occurring in respiratory as well as peripheral muscles in COPD patients. These changes are particular for each muscle territory or compartment. Respiratory muscles predominantly undergo structural adaptive changes.

Metabolic characteristics of the deltoid muscle in patients with chronic obstructive pulmonary disease.

The purpose of this study was to analyse key enzyme activities of the deltoid muscle (DM) in chronic obstructive pulmonary disease (COPD) patients. The activities of one oxidative enzyme (citrate synthase (CS)), two glycolytic enzymes (lacatate dehydrogenase (LD); and phosphofructokinase (PFK)) and one enzyme related to the use of energy stores (creatine kinase (CK)) were determined in the DM of 10 patients with COPD and nine controls. Exercise capacity (cycloergometry) and the handgrip strength were also evaluated.

[Metabolic activity of the external intercostal muscle of patients with COPD].

Introduction: The external intercostal muscle is a relevant contributor to ventilatory work in situations of overloading. Like other respiratory muscles, the external intercostal muscle seems to undergo a process of structural remodeling to adapt to a situation of functional disadvantage. However, findings from published studies of morphology have differed to a certain degree.

[Mechanical and metabolic reproducibility of resistance test of expiratory muscles with incremental threshold loading].

Background: The study of respiratory muscle endurance has mainly focused on inspiratory muscles. A new method to measure expiratory muscle endurance, through incremental threshold loading using a weighted plunger valve, has recently been described.

Objectives: To evaluate the mechanical features of the plunger valve and the reproducibility of the method from the standpoint of both mechanics and metabolism.

[Features of patients with bronchial asthma seen at the emergency department of a referral hospital in a semirural area].

Unlabelled: Bronchial asthma is a chronic disease whose prevalence and severity is increasing. Appropriate treatment of exacerbation seems to affect the subsequent course of disease.

Objectives: To assess the extent of application of guidelines for treating exacerbations of asthma and to describe the clinical and epidemiological characteristics of patients.

Expression of myosin heavy-chain isoforms in the respiratory muscles following inspiratory resistive breathing.

We investigated the effect of inspiratory resistive breathing (IRB) on the expression of the genes encoding fast and slow isoforms of myosin heavy chain (MyHC) in respiratory muscles. Eleven mongrel dogs were studied for baseline MyHC messenger RNA (mRNA) expression, seven of which were also used to study the effects of IRB. For this latter objective, awake and spontaneously breathing animals were subjected to 2 h of IRB (80 cm H(2)O/L/s) per day for four consecutive days.

[Obtaining samples of the human diaphragm during upper laparotomy. A structural analysis].

Unlabelled: The diaphragm seems to undergo adaptive structural change in chronic obstructive pulmonary disease. The possibility of obtaining muscle specimens is limited, however, particularly when respiratory function is severely affected.

Objective: To assess the viability of a new technique for obtaining diaphragm muscle samples appropriate for structural assessment even from patients with severe functional change, and to study the size of fibers in relation to severity of disease.

[The characteristics of the mechanical activity of the respiratory muscles during the diaphragmatic respiration technic].

Unlabelled: Noteworthy among breathing training techniques is so-called diaphragmatic breathing. In spite of the technique's name, however, little is known of the functional characteristics of this ventilatory method.

Objective: To asses the mechanics of respiratory muscles, particularly diaphragm muscles, during diaphragmatic breathing in patients with severe chronic obstructive pulmonary disease (COPD).

[Capillary density and respiratory function in the external intercostal muscle].

Unlabelled: Changes in lung function have been related to adaptive structural modifications in respiratory muscles.

Objective: To evaluate the capillary density (Dcap) of the external intercostal muscle in patients with chronic obstructive pulmonary disease (COPD), and its possible relation to respiratory function.

Methods: Forty-two individuals (61 +/- 9 years old) underwent conventional lung function testing and evaluation of respiratory muscles (maximum pressures at rest and a tolerance test using Martyn's technique).

[Respiratory muscle force and resistance in patients with SAHS. The effect of using nighttime CPAP].

Unlabelled: During nighttime episodes of obstructive apnea in patients with sleep apnea-hypopnea syndrome (SAHS), repeated and progressive inspiratory efforts are made. Such intense nighttime activity can have a deleterious effect on daytime function of respiratory muscles.

Objective: The objective of this study was to evaluate daytime respiratory muscle function in a group of SAHS patients before and after two months of treatment with nighttime continuous positive airway pressure (CPAP).

[Diaphragmatic function during exercise in patients with severe COPD].

Unlabelled: Ventilatory requirements increase during exercise. The respiratory muscles of patients with chronic obstructive pulmonary disease (COPD) are at a particular disadvantage when dealing with such increased demand. The objective of this study was to evaluate the changes in respiratory muscles brought on by exercise in such patients.

Subcellular adaptation of the human diaphragm in chronic obstructive pulmonary disease.

Pulmonary hyperinflation impairs the function of the diaphragm in patients with chronic obstructive pulmonary disease (COPD). However, it has been recently demonstrated that the muscle can counterbalance this deleterious effect, remodelling its structure (i.e.

Structure and function relationships of the respiratory muscles.

Potential relationships between the structure of the diaphragm and external intercostals and several indices of respiratory muscle function, lung function and nutrition in 27 patients (61+/-10 yrs of age) subjected to thoracotomy as a result of a lung neoplasm have been investigated. Prior to surgery the nutritional status of the patients was assessed and lung function (spirometry, lung volumes, transfer factor of the lungs for carbon monoxide, arterial blood gases) and respiratory muscle function (maximal inspiratory pressure (MIP) and diaphragmatic function were measured). Biopsies of the diaphragm (and external intercostals) were obtained during surgery.

[Fiber morphometry of the external intercostal muscle. Comparison of dominant and nondominant sides in patients with severe COPD].

The general morphometric characteristics of the external intercostal muscle (EIM) of patients with chronic respiratory disease have been well described. Because this muscle is highly accessible, it can provide an ideal model for longitudinal studies using consecutive biopsies of both sides. Whether or not the EIM fiber phenotype is homogeneous on dominant (D) and non dominant (ND) sides is unknown, however.

[Cellular homogeneity in diverse portions of the diaphragm].

The diaphragm is the main inspiratory muscle. It is composed of two parts, the costal and crural, with both anatomical and functional differences. The general morphometric characteristics of the diaphragm have been described in various species but homogeneity throughout the muscle has not been adequately studied.

Myosin gene expression in the respiratory muscles.

Myosin is one of the basic structural components of skeletal muscles. Its interaction with actin results in muscle contraction. The myosin molecule is composed of two heavy (MyHC) and two light chains (MyLC) that, together with the adenosine triphosphatase (ATPase) activity, determine the functional characteristics of the fibre.

Diaphragm muscle fiber injury after inspiratory resistive breathing.

Five awake previously tracheotomized mongrel dogs were challenged with inspiratory resistive breathing (IRB). The mean peak tracheal pressure = -35.4 +/- 1.

Selective diaphragmatic mitochondrial abnormalities in a patient with marked air flow obstruction.

There is increasing evidence that exercise overload induces changes in skeletal muscle structure and function. Recent studies suggest that muscle mitochondria could be involved either as the result or the origin of these changes. This study describes a case of a patient with marked air flow obstruction related to chronic obstructive pulmonary disease, in which large aggregates of mitochondria were found in diaphragm muscle fibers.

[Muscle relaxants in the morphometric study of the respiratory muscles in human beings].

The morphological examination of respiratory muscle can be affected by muscular contraction following biopsy. Most morphometric studies of respiratory muscles, however, have been carried out without taking into account this factor, the effect of which can be reduced by using relaxants when taking samples. Objective.

Effects of interpleural bupivacaine on respiratory muscle strength and pulmonary function.

Background: Several reports suggest that interpleural local anesthetics may have deleterious effects on respiratory function. The current study investigated the effects of interpleural bupivacaine on human respiratory muscles and lung function.

Methods: Thirteen patients (55 +/- 4 yr old) with normal respiratory function and scheduled for cholecystectomy entered the study before surgery.

Activity of latissimus dorsi muscle during inspiratory threshold loads.

The ability of the latissimus dorsi muscle (LD) to participate as an accessory inspiratory muscle has been the subject of controversy. Electromyographic (EGM) activity of LD was evaluated in 11 healthy subjects (aged 30 +/- 2 yrs; forced expiratory volume in one second (FEV1) 106 +/- 5% predicted; maximal inspiratory pressure (Pmax), 120 +/- 6 cmH2O) under different breathing conditions. The ipsilateral biceps brachii was chosen as the control muscle.

Structure of the latissimus dorsi muscle and respiratory function.

The aim of this study was to evaluate whether respiratory function influences the structure of the latissimus dorsi muscle (LD). Twelve patients (58 +/- 10 yr) undergoing thoracotomy were studied. Lung and respiratory muscle function were evaluated before surgery.