Objectives: Here, we investigated the effects of hyperventilation on acute lung injury (ALI) in spontaneously breathing rats. Methods: Wistar rats were randomized to receive either intraperitoneal lipopolysaccharides (LPS) or saline, and intravenous infusion of NH4Cl (to induce metabolic acidosis and hyperventilation) or saline. Four groups were established: control-control (C-C), control-hyperventilation (C-HV), LPS-control (LPS-C), and LPS-hyperventilation (LPS-HV). Venous blood gases were collected before and after NH4Cl infusion and analyzed to confirm the presence of metabolic acidosis and hyperventilation. After euthanasia, lung injury was assessed using the ALI score, morphometric quantification of perivascular edema, neutrophil counts in the bronchoalveolar lavage, and mRNA expression of biological markers in the lung tissue. Results: Hyperventilation induced inflammatory lung injury in previously healthy lungs and exacerbated injuries previously induced by LPS (ALI score: C-C=0.14 [IQR 0.12; 0.14]; C-HV=0.36 [IQR 0.31; 0.37]; LPS-C=0.51 [IQR 0.50; 0.54]; LPS-HV=0.58 [IQR 0.56; 0.62]; p<0.01). Perivascular edema, neutrophil counts in bronchoalveolar lavage, and amphiregulin mRNA expression were higher in the LPS-HV group compared to the control group. Conclusions: Hyperventilation increased inflammatory injury in rats with ALI during spontaneous ventilation. These results suggest that the impact of vigorous spontaneous breathing efforts on worsening inflammatory lung injury warrants further investigation.

Keywords: acute lung injury, acute respiratory distress syndrome, spontaneous breathing, hyperventilation, lung injury.

Objective: Silicosis is a pneumoconiosis characterized by fibrosis of the lung parenchyma caused by the inhalation of silica particles. Silica dust inhalation is associated with inflammation and induction of oxidative stress in the lungs. This oxidative stress affects telomeres, which are short tandem DNA repeats that cap the end of linear chromosomes. We aimed to determine whether telomere length (TL) correlates with silicosis or severity of silicosis in silica-exposed workers in Brazil. Methods: We included 200 men in southeastern Brazil: 100 with silicosis and 100 who had not been exposed to silica. We extracted DNA from buccal cells and assessed TL by multiplex quantitative polymerase chain reaction. Results: The median TL was significantly shorter in the patients with silicosis than in the unexposed controls (p < 0.0001), although it did not differ between the patients with simple silicosis and those with complicated silicosis (p = 0.961). We also found that, in patients with silicosis, TL was influenced by smoking (p = 0.034) and by a history of personal protective equipment use in the workplace (p = 0.002). Conclusions: Silica exposure appears to have an impact on TL, which was found to be shorter in patients with silicosis than in unexposed controls. Further studies are needed in order to confirm the impact that oxidative stress caused by silica inhalation has on telomeres.

Keywords: Silicosis; Oxidative stress; Inflammation; Telomere.

Objective: A significant number of patients with chronic thromboembolic pulmonary hypertension (CTEPH) are not eligible for pulmonary endarterectomy and may be treated with balloon pulmonary angioplasty (BPA). Although BPA programs have recently been developed in Brazil, no results have yet been published. The objective of this study was to assess the clinical and hemodynamic progression of the first patients treated with BPA at our center. Methods: This was an observational study of 23 patients with CTEPH enrolled in the BPA program of a specialized center in Brazil between 2015 and 2020. Results: After a mean of 5.6 ± 1.3 sessions and 11 ± 2.8 treated segments/patient (at a mean of 6.7 ± 2.9 months post-BPA), there was a 26% decrease in mean pulmonary artery pressure (51 ± 11 vs. 38 ± 11 mmHg; p < 0.0001), a 43% decrease in pulmonary vascular resistance (10 ± 3.7 vs. 5.7 ± 3.3 WU; p < 0.0001), and a 22.5% increase in the cardiac index (2.38 ± 0.6 vs. 2.95 ± 0.6 L/min/m2; p < 0.0001). There was an increase in the six-minute walk distance and an improvement in functional class. Acute lung injury with clinical manifestations was observed after 7% of the BPA sessions. None of the patients required intubation. During a mean outpatient follow-up period of 38 ± 22 months, two patients were referred for additional BPA sessions due to clinical worsening and new hospitalizations. Two deaths were recorded (due to CTEPH progression and gastrointestinal bleeding, respectively). Conclusions: Among this first group of patients treated with BPA in Brazil, there was significant short- and long-term clinical improvement, together with a low frequency of complications.

Keywords: Hypertension, pulmonary; Pulmonary embolism; Angioplasty, balloon.

Objective: To evaluate the available evidence comparing the use of the bedaquiline, pretomanid, linezolid, and moxifloxacin (BPaLM) regimen for 6 months with that of standard-of-care regimens for patients with multidrug-resistant or rifampin-resistant tuberculosis (MDR/RR-TB). Methods: This was a systematic review of clinical trials comparing the use of the BPaLM regimen with the standard of care in patients with MDR/RR-TB. The main outcome measure was an unfavorable endpoint (a composite of death, treatment failure, treatment discontinuation, loss to follow-up, and recurrence), and secondary outcome measures included adverse events and serious adverse events. We searched the MEDLINE, EMBASE, Google Scholar, LILACS, and ClinicalTrials.gov databases, from their inception to January 31, 2024, with no limitation as to language or year of publication. The risk of bias was assessed by using the Cochrane risk-of-bias tool, and the quality of evidence was based on the Grading of Recommendations Assessment, Development and Evaluation approach. Results: A total of 3,668 studies were retrieved; only one (a randomized clinical trial) met the inclusion criteria and was included. In patients with MDR/RR-TB, treatment with the BPaLM regimen, when compared with the standard of care, reduced the risk of an unfavorable outcome (composite, number needed to treat [NNT] = 7); early treatment discontinuation (NNT = 8); adverse events and discontinuation (NNT = 12); and serious adverse events (NNT = 5). Conclusions: This systematic review of the use of BPaLM in patients with MDR/RR-TB, although it included only one study, showed that BPaLM is more effective than is the standard of care and has a better safety profile. That has major implications for guidelines on the treatment of MDR/RR-TB.

Keywords: Tuberculosis, multidrug-resistant; Antitubercular agents; Diarylquinolines; Linezolid; Moxifloxacin; Nitroimidazoles.