Joan Minguella

Oxidised proteins and superoxide anion production in the diaphragm of severe COPD patients.

In the diaphragms of chronic obstructive pulmonary disease (COPD) patients, the nature of oxidatively modified proteins and superoxide anion production were explored. Diaphragm specimens were obtained through thoracotomy because of localised lung lesions in COPD patients (16 severe and eight moderate) and 10 control subjects. Lung and respiratory muscle functions were evaluated. Oxidised proteins were identified using immunoblotting and mass spectrometry. Protein and activity levels of the identified proteins were determined using immunoblotting and activity assays. Lucigenin-derived chemiluminescence signals in a luminometer were used to determine superoxide anion levels in muscle compartments (mitochondria, membrane and cytosol) using selective inhibitors. In severe COPD patients compared with controls, respiratory muscle function was impaired; creatine kinase, carbonic anhydrase III, actin and myosin were oxidised; myosin carbonylation levels were increased five-fold; creatine kinase content and activity and myosin protein were reduced; superoxide anion levels were increased in both mitochondria and membrane compartments; and the percentage of superoxide anion inhibition achieved by rotenone was significantly greater. In severe COPD patients, oxidation of diaphragm proteins involved in energy production and contractile performance is likely to partially contribute to the documented respiratory muscle dysfunction. Furthermore, generation of the superoxide anion was increased in the diaphragms of these patients.

Inflammatory cells and apoptosis in respiratory and limb muscles of patients with COPD

Discrepancies exist regarding the involvement of cellular inflammation and apoptosis in the muscle dysfunction of chronic obstructive pulmonary disease (COPD) patients with preserved body composition. We explored whether levels of inflammatory cells and apoptosis were increased in both respiratory and limb muscles of COPD patients without nutritional abnormalities. In the vastus lateralis, external intercostals, and diaphragms of severe and moderate COPD patients with normal body composition, and in healthy subjects, intramuscular leukocytes and macrophage levels were determined (immunohistochemistry). Muscle structure was also evaluated. In the diaphragm and vastus lateralis of severe and moderate COPD patients and controls, apoptotic nuclei were explored using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay, electron microscopy, and caspase-3 expression. In COPD patients compared with controls, diaphragm and intercostal levels of inflammatory cells were extremely low and not significantly different. However, in the vastus lateralis of the severe patients, inflammatory cell counts, although also very low, were significantly greater. In those patients, TUNEL-positive nuclei levels were also significantly greater in diaphragms and vastus lateralis. A significant inverse relationship was found between quadriceps TUNEL-positive nuclei levels and muscle force. Ultrastructural apoptotic nuclei revealed no differences in respiratory or limb muscles between COPD patients and controls. Muscle caspase-3 expression did not differ between patients and controls. In severe COPD patients with preserved body composition, while increased apoptotic nuclei seems to be a contributor to their muscle dysfunction, cellular inflammation does not. The increased numbers of TUNEL-positive nuclei in their muscles suggest that they may also be exposed to a continuous repair/remodeling process.

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. On average, patients showed mild airflow limitation (forced expiratory volume in one second (FEV1), 70+/-14% of predicted value, FEV1/forced vital capacity (FVC), 70+/-9%) with some air trapping (residual volume (RV), 139+/-50% pred) and normal gas exchange (arterial oxygen tension (Pa,O2), 11.3+/-1.33 kPa (85+/-10 mmHg)) and arterial carbon dioxide tension (Pa,CO2) 5.4+/-0.5 kPa (40.6+/-4 mmHg). MIP was 77+/-25% pred; maximal transdiaphragmatic pressure was 90+/-27 cmH2O. Most morphometric measurements of the diaphragm and external intercostals were within the range of values reported previously in other skeletal muscles. The size of the fibres of these two respiratory muscles was positively related (p<0.05) to MIP (% pred). There were no significant relationships between the structure of both muscles and nutritional status or any index of lung function. In conclusion, in the population studied, the fibre size of the diaphragm and external intercostals appears to relate to their ability to generate force.

Multiple independent primary cancers do not adversely affect survival of the lung cancer patient

OBJECTIVE Diagnosis of multiple independent primary cancers is increasing in many settings. Objectives of this study were to analyze clinical characteristics, organ location, and prognosis associated with the presentation of multiple independent primaries when a lung cancer is involved. METHODS We analyzed all patients with a histology-proven diagnosis of lung cancer registered from January 1990 to December 2004 at the Tumor Registry of the Hospital del Mar, Barcelona. We compared 1686 patients presenting a lung cancer as unique primary versus 228 patients presenting a lung cancer and another independent primary. Cofactors included age, sex, smoking habit, lung cancer histology and stage, type and intention of treatment, organ location of the other cancer, and survival from the date of lung cancer diagnosis. RESULTS Seventy percent of the other cancers were tobacco-related. Independent risk factors of cancer multiplicity were smoking (OR: 3.99; 95% CI: 1.4-11.2), lung cancer stages I (OR: 1.84; 95% CI: 1.2-2.9) and II (OR: 3.25; 95% CI: 1.7-6.3), and older age (OR: 3.11; 95% CI: 1.9-5.1). Once adjusted by age and sex, the main determinant of survival was lung cancer stage rather than cancer multiplicity. However, patients with multiple cancers presented a slightly better survival than patients with a lung cancer as unique primary. When analyzed by subgroups, survival was higher in patients with the lung cancer first (HR: 0.44; 95% CI: 0.24-0.80), and in patients with the other cancer first (HR: 0.80; 95% CI: 0.65-0.99), but it was not different in the patients with a lung cancer and a synchronous other cancer (HR: 0.80; 95% CI: 0.52-1.15). CONCLUSIONS The risk of developing a second independent cancer was strongly associated with tobacco smoking. Cancer multiplicity was not associated with a worse prognosis. As a consequence, when a first primary tobacco-related cancer is treated with curative intention, patients should be closely followed up for an early diagnosis of a possible new independent cancer; and if diagnosed, treatment to cure should be considered as the first option.

Dual morphometrical changes of the deltoid muscle in patients with COPD.

The present study was specifically aimed at evaluating if the structure of the deltoid muscles is modified in patients with chronic obstructive pulmonary disease (COPD). Twenty-eight male volunteers (61+/-13 yr) were assigned, according to pulmonary function, to either the COPD (n=14, FEV(1)=22-74%pred) or control group (n=14, FEV(1)=83-121%pred). Biopsies from non-dominant deltoid muscle were obtained and processed for morphometric analysis of the fibre types. Both type I and type II muscle fibres were distributed in the typical mosaic pattern. The mean value of the fibre size was within the normal range. However, three differentiated modes were observed in the deltoid from COPD patients: a central mode of normal sized fibres, a mode of atrophic fibres and a mode of hypertrophic fibres. This observation was evident even within single fascicles and especially prevalent in the most severe COPD patients. We conclude that factors with opposite effect (promotion of either atrophy or hypertrophy) exert relevant roles in the histomorphometrical characteristics of the deltoid muscles in COPD patients.

Analysis of Respiratory Muscle Structure and Tumor Necrosis and Insulin-Like Growth Factor Expression in Chronic Obstructive Pulmonary Disease: Are Samples Valid if Obtained During Thoracotomy Performed Because of Localized Pulmonary Neoplasia?

OBJECTIVE Various methods have been used to obtain samples to study the structure of human respiratory muscles and the expression of diverse substances in them. Samples are most often obtained from autopsies, from muscle biopsies during thoracotomy performed because of a localized pulmonary lesion (TLL), and from ambulatory thoracoscopic biopsy in patients free of comorbidity (AT). The disadvantage of the first 2 of these methods lies in the possibility of interference from factors related to the patients death in the first case or from the disease that necessitated surgery in the second. Although AT is free from the disadvantages of the other 2 methods, it is impossible to obtain samples of the diaphragm the principal respiratory muscle with this procedure. The objective of this study was to analyze the fibrous structure of the external intercostal muscle of patients with chronic obstructive pulmonary disease and to quantify the expression of the principal inflammatory cytokine tumor necrosis factor alpha (TNF-alpha)- and of insulin-like growth factor (IGF-1) in the same muscle, comparing the results obtained with TLL and AT samples. METHODS Prospective and consecutive samples were taken of the external intercostal muscle (fifth space, anterior axillary line) in 15 patients with chronic obstructive pulmonary disease (mean [SD] age 66 [6] years; forced expiratory volume in 1 second 49% [9%] of predicted; PaO2 75 [9] mm Hg). Samples were taken during TLL (8 patients, all with pulmonary neoplasms but carefully selected in order to rule out systemic effects) or TA (7 patients). Patients with serious comorbidity were excluded from the second group. Samples were processed for structural analysis of fibers (immunohistochemical and enzymatic histochemical) and genetic expression of TNF-alpha and IGF-1 (real-time polymerase chain reaction). RESULTS No differences in the structure of fibers were found between the 2 groups. No differences were observed in the expression of TNF-alpha or IGF-1. CONCLUSIONS Using rigorous criteria, the TLL method appears to be suitable for studying the structural characteristics and expression of inflammatory cytokines and growth factors in the external intercostal muscle. Moreover, it can also be inferred that TLL is probably also useful for obtaining samples of the diaphragm, a muscle which cannot currently be sampled by any alternative method.

A Collaborative Project to Bridging the Gap between Basic and Clinical Teachers: The Opinion of Medical Students

The organization of medical curricula with a clear distinction between basic and clinical subjects makes it difficult for teachers to collaborate and teach students in an integrated way. We designed a new subject, Integrated Medicine, to overcome such limitations. Here, we describe the evaluation of the first three years of running the experience, as well as the opinion of the first group of students in their sixth year. Three cohorts of first-year medical students and eight teachers, as well as a group of students of sixth year , participated in the experiment. Students worked following the problem-based learning approach. Their satisfaction, their subjective improvement of content knowledge in basic and clinical fields, and their belief about the accomplishment of educational objectives were evaluated. The results showed a high level of satisfaction, increased content knowledge, and improvement in solving problems, searching for relevant information, team working, and oral and written communication skills. Students of sixth year agreed that the subject helped them to better understand the clinical manifestations of disease, the diagnosis process, and therapeutic approaches. In conclusion, experiences such as Integrated Medicine may enhance the integration of knowledge by the joint work of basic and clinical teachers.