This study shows that oxidative stress rather than nitric oxide is likely to be involved in the respiratory muscle dysfunction in severe COPD.

Injury of the diaphragm may have clinical relevance having been reported in cases of sudden infant death syndrome or fatal asthma. However, examination of diaphragm injury after acute inspiratory loading has not been reported. The purpose of this study was to determine whether an acute inspiratory overload induces injury of the human diaphragm and to determine if diaphragm from chronic obstructive pulmonary disease (COPD) is more susceptible to injury. Eighteen patients with COPD and 11 control patients with normal pulmonary function (62 +/- 10 yr) undergoing thoracotomy or laparotomy were studied. A threshold inspiratory loading test was performed prior to surgery in a subset of seven patients with COPD and five control patients. Samples of the costal diaphragm were obtained during surgery and processed for electron microscopy analysis. Signs of sarcomere disruption were found in all diaphragm samples. The range of values of sarcomere disruption was wide (density: 2-45 abnormal areas/100 microm(2); area fractions: 1.3-17.3%), significantly higher in diaphragm from patients with COPD (p < 0.05) and with the greatest injury after inspiratory loading. We conclude that sarcomere disruption is common in the human diaphragm, is more evident in patients with COPD, and is higher after inspiratory loading, especially in the diaphragm of those with COPD.

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.

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. changing the proportion of different types of fibres). The aim of this study was to investigate whether the functional impairment present in COPD patients can be associated with structural subcellular changes of the diaphragm.Twenty individuals (609 yrs, 11 COPD patients and 9 subjects with normal spirometry) undergoing thoracotomy were included. Nutritional status and respiratory function were evaluated prior to surgery. Then, small samples of the costal diaphragm were obtained and processed for electron microscopy analysis.COPD patients showed a mean forced expiratory volume in one second (FEV1) of 609% predicted, a higher concentration of mitochondria (n mit ) in their diaphragm than controls (0.620.16 versus 0.460.16 mitochondrial transections (mt) . mm -2 , p<0.05). On the other hand, subjects with air trapping (residual volume (RV)/total lung capacity (TLC) >37%) disclosed not only a higher n mit (0.630.17 versus 0.430.07 mt . mm -2 , p<0.05) but shorter sarcomeres (L sar ) than subjects without this functional abnormality (2.080.16 to 2.270.15 mm, p<0.05). Glycogen stores were similar in COPD and controls. The severity of airways obstruction (i.e. FEV1) was associated with n mit (r=-0.555, p=0.01), while the amount of air trapping (i.e. RV/TLC) was found to correlate with both n mit (r=0.631, p=0.005) and L sar (r=-0.526, p<0.05). Finally, maximal inspiratory pressure (PI,max) inversely correlated with n mit (r-0.547, p=0.01).In conclusion, impairment in lung function occurring in patients with chronic obstructive pulmonary disease is associated with subcellular changes in their diaphragm, namely a shortening in the length of sarcomeres and an increase in the concentration of mitochondria. These changes form a part of muscle remodelling, probably contributing to a better functional muscle behaviour. Eur Respir J 1999; 13: 371±378. Chronic obstructive pulmonary disease (COPD) is a respiratory condition mainly characterized by persistent airflow limitation [1]. It affects >5% of the general population [2], is a cause of permanent disability and constitutes one of the leading and increasing causes of death in developed countries [3].The function of the diaphragm, the main respiratory muscle, can be impaired in patients with COPD owing to both airways obstruction and pulmonary hyperinflation (air trapping) [4±6]. However, it has been demonstrated that this deleterious effect can be partially counterbalanced by the muscle [7]. TAMAOKI [8] found that fibres were hypertrophic in the diaphragm of guinea-pigs with elastaseinduced emphysema. Recently, LEVINE et al.[9] have demonstrated that patients with severe COPD show a higher percentage of type I fibres in their diaphragm than subjects with normal lung function or mild COPD. These and other chan...

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.

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.

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The prognostic value of p53 and c-erbB-2 immunostaining and preoperative serum levels of CEA and CA125 was investigated in a prospective multicentric study including 465 consecutive non-small cell lung cancer (NSCLC) patients with resectable tumors. Four end-points were used: lung cancer death, first relapse (either locoregional or metastasis), locoregional recurrence and metastasis development. Standard statistical survival methods (Kaplan-Meier and Cox regression) were used. The specificity of the prognostic effect across different types of tumors was also explored, as had been planned in advance. Our results showed, once again, that pathological T and N classifications continue to be the strongest predictors regarding either relapse or mortality. Three of the studied markers seemed to add further useful information, however, but in a more specific context. For example, increased CEA concentration defined a higher risk population among adenocarcinomas but not among people with squamous tumors; and p53 overexpression implied a worse prognosis mainly in patients with well differentiated tumors. The analysis of type of relapse proved to be very informative. Thus, CA125 level was associated with a worse prognosis mainly related with metastasis development. Another interesting result was the influence of smoking, which showed a clear dose-response relationship with the probability of metastasis. For future studies, we recommend the inclusion of different endpoints, namely considering the relationship of markers with the type of relapse involved in lungcancer recurrence. They can add useful information regarding the complex nature of prognosis. Prognosis for non-small cell lung cancer (NSCLC) has remained disappointing over the last decades, even in localized stages that are amenable to curative surgery. 1 Recurrence rates among patients with resectable NSCLC are substantial, 2-4 and only around 50% of them will be alive after 5 years. 5 The clinical or pathologic TNM staging (T, primary tumor; N, regional lymph nodes; M, distant metastasis) does not always provide a satisfactory explanation for differences in relapse and survival. It is of major importance, however, to be able to anticipate a bad prognosis to prescribe an active chemotherapy or radiotherapy adjuvant program. 6,7 In this context, a large number of articles have been published proposing the incorporation of different prognostic markers in clinical practice, 8 but the interpretation and integration of their results is hampered by methodological problems. Many studies included a low number of patients, and very few examined more than 1 or 2 markers. Furthermore, the majority are retrospective cohorts, where the quality of the follow-up is uncertain and the possibility of a selection bias cannot be ruled out. 9 Prognostic studies try to identify one or more variables that might be useful to classify a heterogeneous population into smaller subgroups with more predictable outcomes. This classification will serve to apply therapy more efficiently, avoiding...