A lung image reconstruction from computed radiography images as a tool to tuberculosis treatment control

Background: Tuberculosis (TB) is an infectious lung disease with high worldwide incidence that severely compromises the quality of life in affected individuals. Clinical tests are currently employed to monitor pulmonary status and treatment progression. The present study aimed to apply a three-dimensional (3D) reconstruction method based on chest radiography to quantify lung-involvement volume of TB acute-phase patients before and after treatment. In addition, these results were compared with indices from conventional clinical exams to show the coincidence level. Methods: A 3D lung reconstruction method using patient chest radiography was applied to quantify lung-involvement volume using retrospective examinations of 50 patients who were diagnosed with pulmonary TB and treated with two different drugs schemes. Twenty-five patients were treated with Scheme I (rifampicin, isoniazid, and pyrazinamide), whereas twenty-five patients were treated with Scheme II (rifampicin, isoniazid, pyrazinamide, and ethambutol). Acute-phase reaction: Serum exams included C-reactive protein levels, erythrocyte sedimentation rate, and albumin levels. Pulmonary function was tested posttreatment. Results: We found strong agreement between lung involvement and serum indices pre- and posttreatment. Comparison of the functional severity degree with lung involvement based on 3D image quantification for both treatment schemes found a high correlation. Conclusions: The present 3D reconstruction method produced a satisfactory agreement with the acute-phase reaction, most notably a higher significance level with the C-reactive protein. We also found a quite reasonable coincidence between the 3D reconstruction method and the degree of functional lung impairment posttreatment. The performance of the quantification method was satisfactory when comparing the two treatment schemes. Thus, the 3D reconstruction quantification method may be useful tools for monitoring TB treatment. The association with serum indices are not only inexpensive and sensitive but also may be incorporated into the assessment of patients during TB treatment.(AU)

Pyrrolidine dithiocarbamate administered during ex-vivo lung perfusion promotes rehabilitation of injured donor rat lungs obtained after prolonged warm ischemia.

Damaged lung grafts obtained after circulatory death (DCD lungs) and warm ischemia may be at high risk of reperfusion injury after transplantation. Such lungs could be pharmacologically reconditioned using ex-vivo lung perfusion (EVLP). Since acute inflammation related to the activation of nuclear factor kappaB (NF-κB) is instrumental in lung reperfusion injury, we hypothesized that DCD lungs might be treated during EVLP by pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB. Rat lungs exposed to 1h warm ischemia and 2 h cold ischemia were subjected to EVLP during 4h, in absence (CTRL group, N = 6) or in presence of PDTC (2.5g/L, PDTC group, N = 6). Static pulmonary compliance (SPC), peak airway pressure (PAWP), pulmonary vascular resistance (PVR), and oxygenation capacity were determined during EVLP. After EVLP, we measured the weight gain of the heart-lung block (edema), and the concentration of LDH (cell damage), proteins (permeability edema) and of the cytokines IL-6, TNF-α and CINC-1 in bronchoalveolar lavage (BAL), and we evaluated NF-κB activation by the degree of phosphorylation and degradation of its inhibitor IκBα in lung tissue. In CTRL, we found significant NF-κB activation, lung edema, and a massive release of LDH, proteins and cytokines. SPC significantly decreased, PAWP and PVR increased, while oxygenation tended to decrease. Treatment with PDTC during EVLP inhibited NF-κB activation, did not influence LDH release, but markedly reduced lung edema and protein concentration in BAL, suppressed TNFα and IL-6 release, and abrogated the changes in SPC, PAWP and PVR, with unchanged oxygenation. In conclusion, suppression of innate immune activation during EVLP using the NF-κB inhibitor PDTC promotes significant improvement of damaged rat DCD lungs. Future studies will determine if such rehabilitated lungs are suitable for in vivo transplantation.

Establishing and delivering pulmonary rehabilitation in rural and remote settings: The opinions, attitudes and concerns of health care professionals.

OBJECTIVE: Pulmonary rehabilitation is recommended for people with chronic lung disease however access remains limited in rural and remote settings. The aim of this project was to explore the perspectives of rural and remote health care professionals regarding the establishment and delivery of pulmonary rehabilitation. SETTING: Rural (NSW) and remote (NT) Australian healthcare settings. PARTICIPANTS: Health care professionals (n = 25) who attended a training program focussing on the delivery of pulmonary rehabilitation. MAIN OUTCOME MEASURE(S): Surveys with open written questions were completed by participants following the training program. Key informants also participated in face-to-face interviews. Thematic analysis was undertaken of data collected on participant opinions, attitudes and concerns regarding the establishment and delivery of pulmonary rehabilitation in their individual situation. RESULTS: Participating health care professionals (predominantly nurses and physiotherapists) identified a number of issues relating to establishing and delivering pulmonary rehabilitation; including staffing, time and case load constraints, patient and community attitudes, lack of professional knowledge and confidence and inability to ensure sustainability. The practicalities of delivering pulmonary rehabilitation, particularly exercise prescription and training, were also important concerns raised. CONCLUSIONS: Lack of health care professional staffing, knowledge and confidence were reported to be factors impacting the establishment and delivery of pulmonary rehabilitation. This study has facilitated a greater understanding of the issues surrounding the establishment and delivery of pulmonary rehabilitation in rural and remote settings. Further research is required to investigate the contribution of health professional training and associated factors to improving the availability and delivery of pulmonary rehabilitation in rural and remote settings.

Locally measured shear moduli of pulmonary tissue and global lung mechanics in mechanically ventilated rats.

This study was aimed at measuring shear moduli in vivo in mechanically ventilated rats and comparing them to global lung mechanics. Wistar rats (n = 28) were anesthetized, tracheally intubated, and mechanically ventilated in supine position. The animals were randomly assigned to the healthy control or the lung injury group where lung injury was induced by bronchoalveolar lavage. The respiratory system elastance E(rs) was analyzed based on the single compartment resistance/elastance lung model using multiple linear regression analysis. The shear modulus (G) of alveolar parenchyma was studied using a newly developed endoscopic system with adjustable pressure at the tip that was designed to induce local mechanostimulation. The data analysis was then carried out with an inverse finite element method. G was determined at continuous positive airway pressure (CPAP) levels of 15, 17, 20, and 30 mbar. The resulting shear moduli of lungs in healthy animals increased from 3.3 ± 1.4 kPa at 15 mbar CPAP to 5.8 ± 2.4 kPa at 30 mbar CPAP (P = 0.012), whereas G was ~2.5 kPa at all CPAP levels for the lung-injured animals. Regression analysis showed a negative correlation between G and relative E(rs) in the control group (r = -0.73, P = 0.008 at CPAP = 20 mbar) and no significant correlation in the lung injury group. These results suggest that the locally measured G were inversely associated with the elastance of the respiratory system. Rejecting the study hypothesis the researchers concluded that low global respiratory system elastance is related to high local resistance against tissue deformation.

Effects of recruitment/derecruitment dynamics on the efficacy of variable ventilation.

Variable (or noisy) ventilation (VV) has been demonstrated in animal models of acute lung injury to be superior to constant (or conventional) ventilation (CV), in terms of improved gas exchange and mitigation of lung injury, for reasons that are not entirely clear. We hypothesized that the efficacy of VV is related to the fact that recruitment and derecruitment of lung units are dynamic processes. To test this hypothesis, we modeled the lung computationally as a symmetrically bifurcating airway tree terminating in elastic units. Each airway was fully open or completely closed, at any point in time, according to its pressure history. The model is able to accurately mimic previous experimental measurements showing that the lungs of mice injured by acid aspiration are better recruited after 60 min of VV than CV. The model also shows that recruitment/derecruitment dynamics contribute to the relative efficacy of VV, provided lung units open more rapidly than they close once a critical opening or closing pressure threshold has been crossed. We conclude that the dynamics of recruitment and derecruitment in the lung may be important factors responsible for the benefits of VV compared with CV.

Lung tissue regeneration after induced injury in Runx3 KO mice.

Runx3 is essential for normal murine lung development, and Runx3 knockout (KO) mice, which die soon after birth, exhibit alveolar hyperplasia. Wound healing, tissue repair, and regeneration mechanisms are necessary in humans for proper early lung development. Previous studies have reported that various signaling molecules, such as pErk, Tgf-beta1, CCSP, pJnk, Smad3, and HSP70 are closely related to wound healing. In order to confirm the relationship between lung defects caused by the loss of function of Runx3 and wound healing, we have localized various wound-healing markers after laser irradiation in wild-type and in Runx3 KO mouse lungs at post-natal day 1. Our results indicate that pERK, Tgf-beta1, CCSP, pJnk, and HSP70 are dramatically down-regulated by loss of Runx3 during lung wound healing. However, Smad3 is up-regulated in the Runx3 KO laser-irradiated lung region. Therefore, the lung wound-healing mechanism is inhibited in the Runx3 KO mouse, which shows abnormal lung architecture, by reduced pErk, Tgf-beta1, CCSP, pJnk, and HSP70 and by induced Smad3.

Efeitos da posição prona no paciente com síndrome da angústia respiratória aguda (sara): metanálise / Metanálise effects of prone position in patients with acute respiratory distress syndrome (ards): meta-analysis

Objetivo: Esta revisão teve como objetivo determinar a eficácia da posição prona sobre a PaO2, FiO2, PaO2/FiO2, PEEP, PaCO2 e mortalidade nos pacientes com Síndrome da Angústia Respiratória Aguda­ SARA, discutindo os efeitos benéficos do posicionamento em prono nos pacientes com SARA. A análise dos dados foi realizada através do teste t de Student, com nível de significância p<0,05.Método: Foram analisados revisões sistemáticas e ensaios clínicos controlados e randomizados, a maioria foi publicado nos últimos sete anos, nas línguas inglesa e portuguesa, tendo como referência as bases de dados MEDLINE (National Library of Medicine) e SCIELO (Scientific Electronic Library Online).Resultados: Após a análise e interpretação dos dados, foi observado que só houve diferença estatisticamente significante (p< 0,05) para os índices de PaO2 e PaO2/FiO2.. As demais variáveis (FiO2, PEEP, PaCO2, mortalidade) não apresentaram valores de "p" significantes.Conclusão: Mais evidências são necessárias para confirmar os reais benefícios do posicionamento em prono. Os resultados parecem ser promissores para beneficiar pacientes com SARA, uma vez que houve melhora da oxigenação com aumento da PaO2, diminuição da lesão pulmonar representada pela melhora da relação PaO2/FiO2, com conseqüente redução da mortalidade.

Objective: This review aimed to determine the effectiveness of the prone position on the PaO2, FiO2, PaO2/FiO2, PEEP, PaCO2 and mortality in patients with respiratory distress syndrome - ARDS, discussing the beneficial effects of the positioning in pronation in patients with ARDS. Data analysis was performed by Student's t test with significance set at 0.05. Methods: We analyzed and systematic reviews and randomized controlled trials, the majority was published in the last seven years, in English and Portuguese, with reference to the databases MEDLINE (National Library of Medicine) and SCIELO (Scientific Electronic Library Online). Results: After analyzing and interpreting data, it was observed that only statistically significant difference (p <0.05) for the rates of PaO2 and PaO2/FiO2 .. The other variables (FiO2, PEEP, PaCO2, mortality) showed no significant p-values. Conclusion: More evidence is needed to confirm the actual benefits in the prone position. The results seem promising to benefit patients with ARDS, since there was improvement in oxygenation with the paO2 increase, decrease in lung injury represented by the improvement of the relationship PaO2/FiO2, with a consequent reduction in mortality