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Nontuberculous mycobacterial pulmonary disease (NTM-PD) is a potentially fatal infectious disease requiring long treatment duration with multiple antibiotics and against which there is no reliable cure. Among the factors that have hampered the development of adequate drug regimens is the lack of an animal model that reproduces the NTM lung pathology required for studying antibiotic penetration and efficacy. Given the documented similarities between tuberculosis and NTM immunopathology in patients, we first determined that the rabbit model of active tuberculosis reproduces key features of human NTM-PD and provides an acceptable surrogate model to study lesion penetration. We focused on clarithromycin, a macrolide and pillar of NTM-PD treatment, and explored the underlying causes of the disconnect between its favorable potency and pharmacokinetics and inconsistent clinical outcome. To quantify pharmacokinetic-pharmacodynamic target attainment at the site of disease, we developed a translational model describing clarithromycin distribution from plasma to lung lesions, including the spatial quantitation of clarithromycin and azithromycin in mycobacterial lesions of two patients on long-term macrolide therapy. Through clinical simulations, we visualized the coverage of clarithromycin in plasma and four disease compartments, revealing heterogeneous bacteriostatic and bactericidal target attainment depending on the compartment and the corresponding potency against nontuberculous mycobacteria in clinically relevant assays. Overall, clarithromycin's favorable tissue penetration and lack of bactericidal activity indicated that its clinical activity is limited by pharmacodynamic, rather than pharmacokinetic, factors. Our results pave the way toward the simulation of lesion pharmacokinetic-pharmacodynamic coverage by multidrug combinations to enable the prioritization of promising regimens for clinical trials.

There has been a recent outbreak of e-cigarette or vaping-associated lung injury (EVALI) but the exact pathophysiology remains unknown. Tetrahydrocannabinol (THC) and vitamin E derivates are the major components in vaping-generated aerosols that are associated with EVALI. So far, there is no standard treatment for EVALI. Most cases are treated with antibiotics and steroids. Counseling for smoking cessation is an integral part of care for EVALI patients. Referral to addiction medicine may be beneficial. Considering the nonspecific presenting symptoms and the growing popularity of vaping devices, providers need to consider EVALI in the differential diagnosis of bilateral patchy ground-glass opacities with respiratory, constitutional, or gastrointestinal symptoms in patients using e-cigarettes. Here, we present four EVALI cases and review the pertinent imaging and pathological findings.

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BACKGROUND: The heterogeneity of populations meeting criteria for ARDS may explain in part why no specific treatment has yet been shown to decrease mortality. To define the pathologic alterations associated with the syndrome, particularly the typical pattern of diffuse alveolar damage (DAD), and to evaluate whether etiologies or precipitating factors were missed, we evaluated patients who died with a clinical diagnosis of ARDS and who had a postmortem examination. METHODS: We conducted a 3-year (2002 to 2004) review of all patients with ARDS (using the American-European Consensus Conference criteria) who died in our ICU and had a postmortem examination. Discrepancies between antemortem and postmortem diagnoses were classified as major and minor using the Goldman classification. RESULTS: Of 9,184 hospital admissions, 376 patients had a clinical diagnosis of ARDS. Of these, 169 died; 69 had a postmortem examination, and 64 of these had complete data for analysis. The main cause of death was multiple organ failure (27 of 64 patients). Postmortem examination revealed DAD in 32 patients (50%), pneumonia without DAD in 16 patients (25%), and invasive pulmonary aspergillosis in 8 patients (12.5%). Major unexpected findings were found in 15 patients (23%): 7 Goldman class I (including 4 cases of invasive pulmonary aspergillosis and 1 of disseminated tuberculosis) and 8 Goldman class II. CONCLUSIONS: In this study, ARDS remains a heterogeneous syndrome because only half of patients with ARDS had typical DAD. Open lung biopsy, if performed, might have led to appropriate therapy and potentially better outcome in five of the patients., Journal Article, info:eu-repo/semantics/published

This review addresses surfactant alterations and treatment in lung transplant ischemia-reperfusion injury. Lung ischemia-reperfusion injury damages the endogenous surfactant system as a result of the production of reactive oxygen species, proteolytic enzymes and (phospho)lipases. Surfactant is composed of phospholipids and proteins and its main function is to reduce the surface tension inside the alveolus. Impairment of surfactant will cause atelectasis, influx of serum proteins, pulmonary edema, decreased lung compliance and impaired gas exchange. Surfactant therapy restores the quantity and composition of surfactant and reduces the inhibitory effect of serum proteins; other effects are that it serves as an antioxidant and anti-inflammatory agent. Pretreatment may be more beneficial than treatment after the development of lung ischemia-reperfusion injury. However, the cost of surfactant must be weighed against the clinical outcome.

We examined the relationship between intrapulmonary particle distribution of carbonaceous and mineral dusts and remodeling of the airways along anatomically distinct airway paths in the lungs of Hispanic males from the central valley of California. Lung autopsy specimens from the Fresno County Coroner's Office were prepared by intratracheal instillation of 2% glutaraldehyde at 30 cm H(2)O pressure. Two distinct airway paths into the apico-posterior and apico-anterior portions of the left upper lung lobe were followed. Tissue samples for histologic analysis were generally taken from the intrapulmonary second, fourth, sixth, and ninth airway generations. Parenchymal tissues beyond the 12th airway generation of each airway path were also analyzed. There was little evidence of visible particle accumulation in the larger conducting airways (generations 2-6), except in bronchial-associated lymphoid tissues and within peribronchial connective tissue. In contrast, terminal and respiratory bronchioles arising from each pathway revealed varying degrees of wall thickening and remodeling. Walls with marked thickening contained moderate to heavy amounts of carbonaceous and mineral dusts. Wall thickening was associated with increases in collagen and interstitial inflammatory cells, including dust-laden macrophages. These changes were significantly greater in first-generation respiratory bronchioles compared to second- and third-generation respiratory bronchioles. These findings suggest that accumulation of carbonaceous and mineral dust in the lungs is significantly affected by lung anatomy with the greatest retention in centers of lung acini. Furthermore, there is significant remodeling of this transitional zone in humans exposed to ambient particulate matter.

We examined the relationship between intrapulmonary particle distribution of carbonaceous and mineral dusts and remodeling of the airways along anatomically distinct airway paths in the lungs of Hispanic males from the central valley of California. Lung autopsy specimens from the Fresno County Coroner's Office were prepared by intratracheal instillation of 2% glutaraldehyde at 30 cm H(2)O pressure. Two distinct airway paths into the apico-posterior and apico-anterior portions of the left upper lung lobe were followed. Tissue samples for histologic analysis were generally taken from the intrapulmonary second, fourth, sixth, and ninth airway generations. Parenchymal tissues beyond the 12th airway generation of each airway path were also analyzed. There was little evidence of visible particle accumulation in the larger conducting airways (generations 2-6), except in bronchial-associated lymphoid tissues and within peribronchial connective tissue. In contrast, terminal and respiratory bronchioles arising from each pathway revealed varying degrees of wall thickening and remodeling. Walls with marked thickening contained moderate to heavy amounts of carbonaceous and mineral dusts. Wall thickening was associated with increases in collagen and interstitial inflammatory cells, including dust-laden macrophages. These changes were significantly greater in first-generation respiratory bronchioles compared to second- and third-generation respiratory bronchioles. These findings suggest that accumulation of carbonaceous and mineral dust in the lungs is significantly affected by lung anatomy with the greatest retention in centers of lung acini. Furthermore, there is significant remodeling of this transitional zone in humans exposed to ambient particulate matter.