Lung
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This article reviews the state of the art about an unclear physiological phenomenon interesting respiratory system tissues, i.e., stress-relaxation. Due to their visco-elastic properties, the tissues do not maintain constant stress under constant deformation. Rather, the stress slowly relaxes and falls to a lower value. ⋯ The effects on stress-relaxation of various biochemical and physical factors are reviewed, including the consequences of body temperature variations, respiratory system inflammations and hyperbaric oxygen exposure, endocrinal factors, circulating blood volume variations, changes in inflation volume and/or flow, changes in intra-abdominal pressure because of pneumoperitoneum or Trendelenburg position. The effects of these factors on stress-relaxation have practical consequences because, depending on visco-elastic pressure amount which is requested to inflate the respiratory system in different conditions, respiratory muscles have to produce different values of inspiratory pressure during spontaneous breathing. High inspiratory pressure values might increase the risk of respiratory failure development on mechanical basis.
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Comparative Study
Relationship between sniff nasal inspiratory pressure and BODE index in patients with COPD.
The aims of this study were to investigate the relationship between sniff nasal inspiratory pressure (SNIP) and severity of chronic obstructive pulmonary disease (COPD) as defined by the BODE index, and to investigate the capacity of different SNIP cutoffs to predict a BODE index score ≥5 (i.e., worse disease severity). ⋯ SNIP is moderately and significantly related to COPD severity as assessed by the BODE index. Moreover, the cutoff point of 63 cmH2O showed the best combination of sensitivity and specificity for predicting worse scores in the BODE index.
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Comparative Study
Evaluation of the extent of pulmonary cysts and their association with functional variables and serum markers in lymphangioleiomyomatosis (LAM).
Although computed tomography (CT) has been used previously to assess disease severity in lymphangioleiomyomatosis (LAM), the associations between the extent of pulmonary cysts on CT and six-minute walk test (6MWT), matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF-D) are not well established. We performed a cross-sectional study to quantify the extent of pulmonary cysts in CT and to establish their correlations with pulmonary function tests (PFTs), 6MWT results, including a composite index (desaturation-distance ratio, DDR), and levels of VEGF-D and MMPs in LAM. ⋯ The severity of pulmonary cystic involvement was mild in this sample of LAM patients and correlated best with airway obstruction, air trapping, reduced DLCO, the DDR index, and desaturation during the 6MWT. Serum VEGF-D cannot be completely defined as a valuable marker of disease severity and there may be a mechanism independent of MMPs to explain the formation of pulmonary cysts.
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Lung cancer is the most common and lethal malignancy in the world. The landmark National lung screening trial (NLST) showed a 20% relative reduction in mortality in high-risk individuals with screening low-dose computed tomography. However, the poor specificity and low prevalence of lung cancer in the NLST provide major limitations to its widespread use. ⋯ Autofluorescence bronchoscopy has been employed in research setting to identify pre-invasive lesions not identified on CT scan. Although these modalities are not yet commercially available in clinic setting, they will be available in the near future and clinicians who care for patients with lung cancer should be aware. In this review, we present up-to-date state of biomarker development, discuss their clinical relevance and predict their future role in lung cancer management.