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Suman PR, Souza LS, Kincheski GC, Melo HM, Machado MN, Carvalho GMC, De Felice FG, Zin WA, Ferreira ST. Lung inflammation induced by silica particles triggers hippocampal inflammation, synapse damage and memory impairment in mice. J Neuroinflammation 2022; 19:303. [PMID: 36527099 PMCID: PMC9756632 DOI: 10.1186/s12974-022-02662-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Considerable evidence indicates that a signaling crosstalk between the brain and periphery plays important roles in neurological disorders, and that both acute and chronic peripheral inflammation can produce brain changes leading to cognitive impairments. Recent clinical and epidemiological studies have revealed an increased risk of cognitive impairment and dementia in individuals with impaired pulmonary function. However, the mechanistic underpinnings of this association remain unknown. Exposure to SiO2 (silica) particles triggers lung inflammation, including infiltration by peripheral immune cells and upregulation of pro-inflammatory cytokines. We here utilized a mouse model of lung silicosis to investigate the crosstalk between lung inflammation and memory. METHODS Silicosis was induced by intratracheal administration of a single dose of 2.5 mg SiO2/kg in mice. Molecular and behavioral measurements were conducted 24 h and 15 days after silica administration. Lung and hippocampal inflammation were investigated by histological analysis and by determination of pro-inflammatory cytokines. Hippocampal synapse damage, amyloid-β (Aβ) peptide content and phosphorylation of Akt, a proxy of hippocampal insulin signaling, were investigated by Western blotting and ELISA. Memory was assessed using the open field and novel object recognition tests. RESULTS Administration of silica induced alveolar collapse, lung infiltration by polymorphonuclear (PMN) cells, and increased lung pro-inflammatory cytokines. Lung inflammation was followed by upregulation of hippocampal pro-inflammatory cytokines, synapse damage, accumulation of the Aβ peptide, and memory impairment in mice. CONCLUSION The current study identified a crosstalk between lung and brain inflammatory responses leading to hippocampal synapse damage and memory impairment after exposure to a single low dose of silica in mice.
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Lucangelo U, Ajčević M, Lena E, Ferluga M, Comuzzi L, Accardo A, Zin WA. On some factors determining the pressure drop across tracheal tubes during high-frequency percussive ventilation: a flow-independent model. J Clin Monit Comput 2020; 35:885-890. [PMID: 32588314 PMCID: PMC7316425 DOI: 10.1007/s10877-020-00548-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 06/11/2020] [Indexed: 11/29/2022]
Abstract
To provide an in vitro estimation of the pressure drop across tracheal tubes (ΔPTT) in the face of given pulsatile frequencies and peak pressures (Pwork) delivered by a high-frequency percussive ventilator (HFPV) applied to a lung model. Tracheal tubes (TT) 6.5, 7.5 and 8.0 were connected to a test lung simulating the respiratory system resistive (R = 5, 20, 50 cmH2O/L/s) and elastic (C = 10, 20, and 50 mL/cmH2O) loads. The model was ventilated by HFPV with a pulse inspiratory peak pressure (work pressure Pwork) augmented in 5-cmH2O steps from 20 to 45 cmH2O, yielding 6 diverse airflows. The percussive frequency (f) was set to 300, 500 and 700 cycles/min, respectively. Pressure (Paw and Ptr) and flow (V’) measurements were performed for all 162 possible combinations of loads, frequencies, and work pressures for each TT size, thus yielding 486 determinations. For each respiratory cycle ΔPTT was calculated by subtracting each peak Ptr from its corresponding peak Paw. A non-linear model was constructed to assess the relationships between single parameters. Performance of the produced model was measured in terms of root mean square error (RMSE) and the coefficient of determination (r2). ΔPTT was predicted by Pwork (exponential Gaussian relationship), resistance (quadratic and linear terms), frequency (quadratic and linear terms) and tube diameter (linear term), but not by compliance. RMSE of the model on the testing dataset was 1.17 cmH2O, r2 was 0.79 and estimation error was lower than 1 cmH2O in 68% of cases. As a result, even without a flow value, the physician would be able to evaluate ΔPTT pressure. If the present results of our bench study could be clinically confirmed, the use of a nonconventional ventilatory strategy as HFPV, would be safer and easier.
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Zin WA, Fortunato RS, Faria CC, Takiya CM, Bastos AC. Inflammatory and Functional Responses Induced by Normobaric and Hyperbaric Hyperoxia in Mice Lungs. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.02756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Zin WA, Caldeira DF, Pinheiro FG, Maciel L, Oliveira DF. Exposure to Fullerene C60 Nanoparticles Impairs Lung Mechanics and Mitochondrial Function. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.02712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Okuro RT, Freire RC, Zin WA, Quagliato LA, Nardi AE. Panic disorder respiratory subtype: psychopathology and challenge tests - an update. ACTA ACUST UNITED AC 2020; 42:420-430. [PMID: 32074230 PMCID: PMC7430397 DOI: 10.1590/1516-4446-2019-0717] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 12/01/2019] [Indexed: 02/06/2023]
Abstract
Panic disorder (PD) pathophysiology is very heterogeneous, and the discrimination of distinct subtypes could be very useful. A subtype based on respiratory symptoms is known to constitute a specific subgroup. However, evidence to support the respiratory subtype (RS) as a distinct subgroup of PD with a well-defined phenotype remains controversial. Studies have focused on characterization of the RS based on symptoms and response to CO2. In this line, we described clinical and biological aspects focused on symptomatology and CO2 challenge tests in PD RS. The main symptoms that characterize RS are dyspnea (shortness of breath) and a choking sensation. Moreover, patients with the RS tended to be more responsive to CO2 challenge tests, which triggered more panic attacks in this subgroup. Future studies should focus on discriminating respiratory-related clusters and exploring psychophysiological and neuroimaging outcomes in order to provide robust evidence to confirm RS as a distinct subtype of PD.
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Magalhães CB, Casquilho NV, Machado MN, Riva DR, Travassos LH, Leal-Cardoso JH, Fortunato RS, Faffe DS, Zin WA. The anti-inflammatory and anti-oxidative actions of eugenol improve lipopolysaccharide-induced lung injury. Respir Physiol Neurobiol 2019; 259:30-36. [DOI: 10.1016/j.resp.2018.07.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/28/2018] [Accepted: 07/07/2018] [Indexed: 11/28/2022]
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Comuzzi L, de Abreu MB, Motta-Ribeiro GC, Okuro RT, Barboza T, Carvalho N, Lucangelo U, Carvalho AR, Zin WA. Regional Lung Recruitability During Pneumoperitoneum Depends on Chest Wall Elastance - A Mechanical and Computed Tomography Analysis in Rats. Front Physiol 2018; 9:920. [PMID: 30057557 PMCID: PMC6053523 DOI: 10.3389/fphys.2018.00920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 06/25/2018] [Indexed: 11/13/2022] Open
Abstract
Background: Laparoscopic surgery with pneumoperitoneum increases respiratory system elastance due to the augmented intra-abdominal pressure. We aim to evaluate to which extent positive end-expiratory pressure (PEEP) is able to counteract abdominal hypertension preventing progressive lung collapse and how rib cage elastance influences PEEP effect. Methods: Forty-four Wistar rats were mechanically ventilated and randomly assigned into three groups: control (CTRL), pneumoperitoneum (PPT) and pneumoperitoneum with restricted rib cage (PPT-RC). A pressure-volume (PV) curve followed by a recruitment maneuver and a decremental PEEP trial were performed in all groups. Thereafter, animals were ventilated using PEEP of 3 and 8 cmH2O divided into two subgroups used to evaluate respiratory mechanics or computed tomography (CT) images. In 26 rats, we compared respiratory system elastance (Ers) at the two PEEP levels. In 18 animals, CT images were acquired to calculate total lung volume (TLV), total volume and air volume in six anatomically delimited regions of interest (three along the cephalo-caudal and three along the ventro-dorsal axes). Results: PEEP of minimal Ers was similar in CTRL and PPT groups (3.8 ± 0.45 and 3.5 ± 3.89 cmH2O, respectively) and differed from PPT-RC group (9.8 ± 0.63 cmH2O). Chest restriction determined a right- and downward shift of the PV curve, increased Ers and diminished TLV and lung aeration. Increasing PEEP augmented TLV in CTRL group (11.8 ± 1.3 to 13.6 ± 2 ml, p < 0.05), and relative air content in the apex of PPT group (3.5 ± 1.4 to 4.6 ± 1.4% TLV, p < 0.03) and in the middle zones in PPT-RC group (21.4 ± 1.9 to 25.3 ± 2.1% TLV cephalo-caudally and 18.1 ± 4.3 to 22.0 ± 3.3% TLV ventro-dorsally, p < 0.005). Conclusion: Regional lung recruitment potential during pneumoperitoneum depends on rib cage elastance, reinforcing the concept of PEEP individualization according to the patient's condition.
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Machado MN, Mazzoli-Rocha F, Casquilho NV, Maron-Gutierrez T, Ortenzi VH, Morales MM, Fortunato RS, Zin WA. Bone Marrow-Derived Mononuclear Cell Therapy in Papain-Induced Experimental Pulmonary Emphysema. Front Physiol 2018. [PMID: 29515461 PMCID: PMC5826278 DOI: 10.3389/fphys.2018.00121] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Murine papain-induced emphysema is a model that reproduces many of the features found in patients. Bone marrow-derived mononuclear cells (BMMC) have already been used to repair the alveolar epithelium in respiratory diseases, but not in the papain model. Thus, we hypothesized that BMMC could prevent the pathophysiological processes in papain-induced experimental emphysema. Female BALB/c mice received intratracheal instillation of 50 μL of saline (S groups) or papain (P groups, 10 IU/50 μl of saline) on days 1 and 7 of the experimental protocol. On the 14th day, 2 × 106 BMMC of male BALB/c mice (SC21 and PC21) or saline (SS21 and PS21) were injected by the jugular vein. Analyses were done on days 14 (S14 and P14) and 21 (SS21, PS21, SC21, and PC21) of the protocol. qPCR evaluated the presence of the Y chromosome in the lungs of BMMC recipient animals. Functional residual capacity (FRC), alveolar diameter, cellularity, elastic fiber content, concentrations of TNF-α, IL-1β, IL-6, MIP-2, KC, IFN-γ, apoptosis, mRNA expression of the dual oxidase (DUOX1 and DUOX2), production of H2O2 and DUOX activity were evaluated in lung tissue. We did not detect the Y chromosome in recipients' lungs. FRC, alveolar diameter, polymorphonuclear cells (PMN) and levels of KC, MIP-2, and IFN-γ increased in P14 and PS21 groups; the changes in the latter were reverted by BMMC. TNF-α, IL-1β e IL-6 were similar in all groups. The amount of elastic fibers was smaller in P14 and PS21 than in other groups, and BMMC did not increase it in PC21 mice. PS21 animals showed increased DUOX activity and mRNA expression for DUOX1 and 2. Cell therapy reverted the activity of DUOX and mRNA expression of DUOX1. BMMC reduced mRNA expression of DUOX2. Apoptosis index was elevated in PS21 mice, which was reduced by cell therapy in PC21. Static compliance, viscoelastic component of elastance and pressure to overcome viscoelasticity were increased in P14 and PS21 groups. These changes and the high resistive pressure found on day 21 were reverted by BMMC. In conclusion, BMMC showed potent anti-inflammatory, antiapoptotic, antioxidant, and restorative roles in papain-triggered pulmonary emphysema.
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Casquilho NV, Moreira-Gomes MD, Magalhães CB, Okuro RT, Ortenzi VH, Feitosa-Lima EK, Lima LM, Barreiro EJ, Soares RM, Azevedo SMFO, Valença SS, Fortunato RS, Carvalho AR, Zin WA. Oxidative imbalance in mice intoxicated by microcystin-LR can be minimized. Toxicon 2018; 144:75-82. [PMID: 29454806 DOI: 10.1016/j.toxicon.2018.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/09/2018] [Accepted: 02/13/2018] [Indexed: 12/19/2022]
Abstract
Microcystins-LR (MC-LR) is a cyanotoxin produced by cyanobacteria. We evaluated the antioxidant potential of LASSBio-596 (LB-596, inhibitor of phosphodiesterases 4 and 5), per os, and biochemical markers involved in lung and liver injury induced by exposure to sublethal dose of MC-LR. Fifty male Swiss mice received an intraperitoneal injection of 60 μL of saline (CTRL group, n = 20) or a sublethal dose of MC-LR (40 μg/kg, TOX group, n = 20). After 6 h the animals received either saline (TOX and CTRL groups) or LB-596 (50 mg/kg, TOX + LASS group, n = 10) by gavage. At 6 h after exposure, respiratory mechanics was evaluated in 10 CTRL and 10 TOX mice: there was a significant increase of all lung mechanics parameters (static elastance, viscoelastic component of elastance and lung resistive and viscoelastic/inhomogeneous pressures) in TOX compared to CTRL. 8 h after saline or MC-LR administration, i.e., 2 h after treatment with LB-596, blood serum levels of alanine aminotransferase and aspartate aminotransferase, activity of superoxide dismutase, catalase, and content of malondialdehyde and carbonyl in lung and liver, NADPH oxidase 2 and 4 mRNA expressions, dual oxidase enzyme activity and H2O2 generation were analyzed in lung homogenates. All parameters were significantly higher in TOX than in the other groups. There was no significant difference between CTRL and TOX + LASS. MC-LR deteriorated lung and liver functions and induced redox imbalance in them, which was prevented by oral administration of LB-596.
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Moreira Gomes MD, Carvalho GMC, Casquilho NV, Araújo ACP, Valença SS, Leal-Cardoso JH, Zin WA. 2,2'-Azobis (2-Amidinopropane) Dihydrochloride Is a Useful Tool to Impair Lung Function in Rats. Front Physiol 2016; 7:475. [PMID: 27812337 PMCID: PMC5071333 DOI: 10.3389/fphys.2016.00475] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/03/2016] [Indexed: 01/24/2023] Open
Abstract
Recently, several studies have reported that respiratory disease may be associated with an increased production of free radicals. In this context, 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH) is a free radical-generating compound widely used to mimic the oxidative stress state. We aimed to investigate whether AAPH can generate lung functional, inflammatory, histological and biochemical impairments in the lung. Wistar rats were divided into five groups and instilled with saline solution (714 μL/kg, CTRL group) or different amounts of AAPH (25, 50, 100, and 200 mg/kg, 714 μL/kg, AAPH groups). Seventy-two hours later the animals were anesthetized, paralyzed, intubated and static elastance (Est), viscoelastic component of elastance (ΔE), resistive (ΔP1) and viscoelastic (ΔP2) pressures were measured. Oxidative damage, inflammatory markers and lung morphometry were analyzed. ΔP1 and Est were significantly higher in AAPH100 and AAPH200 than in the other groups. The bronchoconstriction indexes were larger in AAPH groups than in CTRL. The area occupied by collagen and elastic fibers, polymorpho- and mononuclear cells, malondialdehyde and carbonyl groups levels were significantly higher in AAPH200 than in CTRL. In comparison to CTRL, AAPH200 showed significant decrease and increase in the activities of superoxide dismutase and catalase, respectively. AAPH augmented the release of pro-inflammatory cytokines IL-1β, IL-6 e TNF-α. Hence, exposure to AAPH caused significant inflammatory alterations and redox imbalance accompanied by altered lung mechanics and histology. Furthermore, we disclosed that exposure to AAPH may represent a useful in vivo tool to trigger lung lesions.
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Abreu MD, Neto AC, Carvalho G, Casquillo NV, Carvalho N, Okuro R, Ribeiro GCM, Machado M, Cardozo A, Silva ASE, Barboza T, Vasconcellos LR, Rodrigues DA, Camilo L, Carneiro LDAM, Jandre F, Pino AV, Giannella-Neto A, Zin WA, Corrêa LHT, Souza MND, Carvalho AR. Does acute exposure to aldehydes impair pulmonary function and structure? Respir Physiol Neurobiol 2016; 229:34-42. [PMID: 27102012 DOI: 10.1016/j.resp.2016.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/28/2016] [Accepted: 04/11/2016] [Indexed: 11/29/2022]
Abstract
Mixtures of anhydrous ethyl alcohol and gasoline substituted for pure gasoline as a fuel in many Brazilian vehicles. Consequently, the concentrations of volatile organic compounds (VOCs) such as ketones, other organic compounds, and particularly aldehydes increased in many Brazilian cities. The current study aims to investigate whether formaldehyde, acetaldehyde, or mixtures of both impair lung function, morphology, inflammatory and redox responses at environmentally relevant concentrations. For such purpose, C57BL/6 mice were exposed to either medical compressed air or to 4 different mixtures of formaldehyde and acetaldehyde. Eight hours later animals were anesthetized, paralyzed and lung mechanics and morphology, inflammatory cells and IL-1β, KC, TNF-α, IL-6, CCL2, MCP-1 contents, superoxide dismutase and catalalase activities were determined. The extra pulmonary respiratory tract was also analyzed. No differences could be detected between any exposed and control groups. In conclusion, no morpho-functional alterations were detected in exposed mice in relation to the control group.
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Lucangelo U, Ajčević M, Accardo A, Borelli M, Peratoner A, Comuzzi L, Zin WA. FLOW-i ventilator performance in the presence of a circle system leak. J Clin Monit Comput 2016; 31:273-280. [PMID: 27062381 DOI: 10.1007/s10877-016-9867-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 03/20/2016] [Indexed: 01/29/2023]
Abstract
Recently, the FLOW-i anaesthesia ventilator was developed based on the SERVO-i intensive care ventilator. The aim of this study was to test the FLOW-i's tidal volume delivery in the presence of a leak in the breathing circuit. We ventilated a test lung model in volume-, pressure-, and pressure-regulated volume-controlled modes (VC, PC, and PRVC, respectively) with a FLOW-i. First, the circuit remained airtight and the ventilator was tested with fresh gas flows of 6, 1, and 0.3 L/min in VC, PC, and PRVC modes and facing 4 combinations of different resistive and elastic loads. Second, a fixed leak in the breathing circuit was introduced and the measurements repeated. In the airtight system, FLOW-i maintained tidal volume (VT) and circuit pressure at approximately the set values, independently of respiratory mode, load, or fresh gas flow. In the leaking circuit, set VT = 500 mL, FLOW-i delivered higher VTs in PC (about 460 mL) than in VC and PRVC, where VTs were substantially less than 500 mL. Interestingly, VT did not differ appreciably from 6 to 0.3 L/min of fresh air flow among the 3 ventilatory modes. In the absence of leakage, peak inspiratory pressures were similar, while they were 35-45 % smaller in PRVC and VC than in PC mode in the presence of leaks. In conclusion, FLOW-i maintained VT (down to fresh gas flows of 0.3 L/min) to 90 % of its preset value in PC mode, which was 4-5 times greater than in VC or PRVC modes.
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Oliveira VR, Mancin VGL, Pinto EF, Soares RM, Azevedo SMFO, Macchione M, Carvalho AR, Zin WA. Repeated intranasal exposure to microcystin-LR affects lungs but not nasal epithelium in mice. Toxicon 2015. [PMID: 26220798 DOI: 10.1016/j.toxicon.2015.07.331] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Microcystin-LR (MC-LR) is a harmful cyanotoxin able to induce adverse outcomes in the respiratory system. We aimed to examine the lungs and nasal epithelium of mice following a sub-chronic exposure to MC-LR. Swiss mice were intranasally instilled with 10 μL of distilled water (CTRL, n = 10) or 6.7 ng/kg of MC-LR diluted in 10 μL of distilled water (TOX, n = 8) during 30 consecutive days. Respiratory mechanics was measured in vivo and histology measurements (morphology and inflammation) were assessed in lungs and nasal epithelium samples 24 h after the last intranasal instillation. Despite the lack of changes in the nasal epithelium, TOX mice displayed an increased amount of PMN cells in the lungs (× 10(-3)/μm(2)), higher lung static elastance (cmH2O/mL), resistive and viscoelastic/inhomogeneous pressures (cmH2O) (7.87 ± 3.78, 33.96 ± 2.64, 1.03 ± 0.12, 1.01 ± 0.08, respectively) than CTRL (5.37 ± 4.02, 26.65 ± 1.24, 0.78 ± 0.06, 0.72 ± 0.05, respectively). Overall, our findings suggest that the nasal epithelium appears more resistant than lungs in this model of MC-LR intoxication.
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Ayala LG, Abreu M, Avila M, Bergamini BC, Neto AC, Zin WA, Neto AG, Carvalho AR. 0548. Effects of sedation and muscle paralysis on inflammation during mechanical ventilation. Intensive Care Med Exp 2014. [PMCID: PMC4798140 DOI: 10.1186/2197-425x-2-s1-p32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Camilo LM, Ávila MB, Cruz LFS, Ribeiro GCM, Spieth PM, Reske AA, Amato M, Giannella-Neto A, Zin WA, Carvalho AR. Positive end-expiratory pressure and variable ventilation in lung-healthy rats under general anesthesia. PLoS One 2014; 9:e110817. [PMID: 25383882 PMCID: PMC4226529 DOI: 10.1371/journal.pone.0110817] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 09/13/2014] [Indexed: 11/25/2022] Open
Abstract
Objectives Variable ventilation (VV) seems to improve respiratory function in acute lung injury and may be combined with positive end-expiratory pressure (PEEP) in order to protect the lungs even in healthy subjects. We hypothesized that VV in combination with moderate levels of PEEP reduce the deterioration of pulmonary function related to general anesthesia. Hence, we aimed at evaluating the alveolar stability and lung protection of the combination of VV at different PEEP levels. Design Randomized experimental study. Setting Animal research facility. Subjects Forty-nine male Wistar rats (200–270 g). Interventions Animals were ventilated during 2 hours with protective low tidal volume (VT) in volume control ventilation (VCV) or VV and PEEP adjusted at the level of minimum respiratory system elastance (Ers), obtained during a decremental PEEP trial subsequent to a recruitment maneuver, and 2 cmH2O above or below of this level. Measurements and Main Results Ers, gas exchange and hemodynamic variables were measured. Cytokines were determined in lung homogenate and plasma samples and left lung was used for histologic analysis and diffuse alveolar damage scoring. A progressive time-dependent increase in Ers was observed independent on ventilatory mode or PEEP level. Despite of that, the rate of increase of Ers and lung tissue IL-1 beta concentration were significantly lower in VV than in VCV at the level of the PEEP of minimum Ers. A significant increase in lung tissue cytokines (IL-6, IL-1 beta, CINC-1 and TNF-alpha) as well as a ventral to dorsal and cranial to caudal reduction in aeration was observed in all ventilated rats with no significant differences among groups. Conclusions VV combined with PEEP adjusted at the level of the PEEP of minimal Ers seemed to better prevent anesthesia-induced atelectasis and might improve lung protection throughout general anesthesia.
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Yoshida T, Torsani V, Gomes S, De Santis RR, Beraldo MA, Costa ELV, Tucci MR, Zin WA, Kavanagh BP, Amato MBP. Spontaneous effort causes occult pendelluft during mechanical ventilation. Am J Respir Crit Care Med 2014; 188:1420-7. [PMID: 24199628 DOI: 10.1164/rccm.201303-0539oc] [Citation(s) in RCA: 306] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
RATIONALE In normal lungs, local changes in pleural pressure (P(pl)) are generalized over the whole pleural surface. However, in a patient with injured lungs, we observed (using electrical impedance tomography) a pendelluft phenomenon (movement of air within the lung from nondependent to dependent regions without change in tidal volume) that was caused by spontaneous breathing during mechanical ventilation. OBJECTIVES To test the hypotheses that in injured lungs negative P(pl) generated by diaphragm contraction has localized effects (in dependent regions) that are not uniformly transmitted, and that such localized changes in P(pl) cause pendelluft. METHODS We used electrical impedance tomography and dynamic computed tomography (CT) to analyze regional inflation in anesthetized pigs with lung injury. Changes in local P(pl) were measured in nondependent versus dependent regions using intrabronchial balloon catheters. The airway pressure needed to achieve comparable dependent lung inflation during paralysis versus spontaneous breathing was estimated. MEASUREMENTS AND MAIN RESULTS In all animals, spontaneous breathing caused pendelluft during early inflation, which was associated with more negative local P(pl) in dependent regions versus nondependent regions (-13.0 ± 4.0 vs. -6.4 ± 3.8 cm H2O; P < 0.05). Dynamic CT confirmed pendelluft, which occurred despite limitation of tidal volume to less than 6 ml/kg. Comparable inflation of dependent lung during paralysis required almost threefold greater driving pressure (and tidal volume) versus spontaneous breathing (28.0 ± 0.5 vs. 10.3 ± 0.6 cm H2O, P < 0.01; 14.8 ± 4.6 vs. 5.8 ± 1.6 ml/kg, P < 0.05). CONCLUSIONS Spontaneous breathing effort during mechanical ventilation causes unsuspected overstretch of dependent lung during early inflation (associated with reciprocal deflation of nondependent lung). Even when not increasing tidal volume, strong spontaneous effort may potentially enhance lung damage.
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Ajčević M, Lucangelo U, Ferluga M, Zin WA, Accardo A. In vitro estimation of pressure drop across tracheal tubes during high-frequency percussive ventilation. Physiol Meas 2014; 35:177-88. [PMID: 24398394 DOI: 10.1088/0967-3334/35/2/177] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Tracheal tubes (TT) are used in clinical practice to connect an artificial ventilator to the patient's airways. It is important to know the pressure used to overcome tube impedance to avoid lung injury. Although high-frequency percussive ventilation (HFPV) has been increasingly used, the mechanical behavior of TT under HFPV has not yet been described. Thus, we aimed at characterizing in vitro the pressure drop across TT (ΔPTT) by identifying the model that best fits the measured pressure-flow (P-V̇) relationships during HFPV under different working pressures (PWork), percussive frequencies and mechanical loads. Three simple models relating ΔPTT and flow (V̇) were tested. Model 1 is characterized by linear resistive [Rtube ⋅ V̇(t)] and inertial [I · V̈(t)] terms. Model 2 takes into consideration Rohrer's approach [K1· V̇(t) + K2 ⋅V̇(t)] and inertance [I ·V̈(t)]. In model 3 the pressure drop caused by friction is represented by the non-linear Blasius component [Kb· V̇(1.75)(t)] and the inertial term [I· V̈(t)]. Model 1 presented a significantly higher root mean square error of approximation than models 2 and 3, which were similar. Thus, model 1 was not as accurate as the latter, possibly due to turbulence. Model 3 presented the most robust resistance-related coefficient. Estimated inertances did not vary among the models using the same tube. In conclusion, in HFPV ΔPTT can be easily calculated by the physician using model 3.
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Mazzoli-Rocha F, Carvalho GMC, Lanzetti M, Valença SS, Silva LFF, Saldiva PHN, Zin WA, Faffe DS. Respiratory toxicity of repeated exposure to particles produced by traffic and sugar cane burning. Respir Physiol Neurobiol 2013; 191:106-13. [PMID: 24280381 DOI: 10.1016/j.resp.2013.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 11/18/2013] [Accepted: 11/19/2013] [Indexed: 11/25/2022]
Abstract
We compared the toxicity of subchronic exposure to equivalent masses of particles from sugar cane burning and traffic. BALB/c mice received 3 intranasal instillations/week during 1, 2 or 4 weeks of either distilled water (C1, C2, C4) or particles (15μg) from traffic (UP1, UP2, UP4) or biomass burning (BP1, BP2, BP4). Lung mechanics, histology and oxidative stress were analyzed 24h after the last instillation. In all instances UP and BP groups presented worse pulmonary elastance, airway and tissue resistance, alveolar collapse, bronchoconstriction and macrophage influx into the lungs than controls. UP4, BP2 and BP4 presented more alveolar collapse than UP1 and BP1, respectively. UP and BP had worse bronchial and alveolar lesion scores than their controls; BP4 had greater bronchial lesion scores than UP4. Catalase was higher in UP4 and BP4 than in C4. In conclusion, biomass particles were more toxic than those from traffic after repeated exposures.
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Carvalho AR, Bergamini BC, Carvalho NS, Cagido VR, Neto AC, Jandre FC, Zin WA, Giannella-Neto A. Volume-Independent Elastance. Anesth Analg 2013; 116:627-33. [DOI: 10.1213/ane.0b013e31824a95ca] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Antonaglia V, Ferluga M, Bianco N, Accolla PP, Zin WA. Respiratory mechanics during repeated lung lavages in pulmonary alveolar proteinosis. Intern Emerg Med 2012; 7 Suppl 2:S109-11. [PMID: 22426811 DOI: 10.1007/s11739-012-0767-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 03/01/2012] [Indexed: 11/29/2022]
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Lucangelo U, Zin WA, Fontanesi L, Antonaglia V, Peratoner A, Ferluga M, Marras E, Borelli M, Ciccolini M, Berlot G. Early Short-Term Application of High-Frequency Percussive Ventilation Improves Gas Exchange in Hypoxemic Patients. Respiration 2012; 84:369-76. [DOI: 10.1159/000334403] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 10/15/2011] [Indexed: 11/19/2022] Open
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Zin WA, Silva AGLS, Magalhães CB, Carvalho GMC, Riva DR, Lima CC, Leal-Cardoso JH, Takiya CM, Valença SS, Saldiva PHN, Faffe DS. Eugenol attenuates pulmonary damage induced by diesel exhaust particles. J Appl Physiol (1985) 2011; 112:911-7. [PMID: 22194320 DOI: 10.1152/japplphysiol.00764.2011] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Environmentally relevant doses of inhaled diesel particles elicit pulmonary inflammation and impair lung mechanics. Eugenol, a methoxyphenol component of clove oil, presents in vitro and in vivo anti-inflammatory and antioxidant properties. Our aim was to examine a possible protective role of eugenol against lung injuries induced by diesel particles. Male BALB/c mice were divided into four groups. Mice received saline (10 μl in; CTRL group) or 15 μg of diesel particles DEP (15 μg in; DIE and DEUG groups). After 1 h, mice received saline (10 μl; CTRL and DIE groups) or eugenol (164 mg/kg; EUG and DEUG group) by gavage. Twenty-four hours after gavage, pulmonary resistive (ΔP1), viscoelastic (ΔP2) and total (ΔPtot) pressures, static elastance (Est), and viscoelastic component of elastance (ΔE) were measured. We also determined the fraction areas of normal and collapsed alveoli, amounts of polymorpho- (PMN) and mononuclear cells in lung parenchyma, apoptosis, and oxidative stress. Est, ΔP2, ΔPtot, and ΔE were significantly higher in the DIE than in the other groups. DIE also showed significantly more PMN, airspace collapse, and apoptosis than the other groups. However, no beneficial effect on lipid peroxidation was observed in DEUG group. In conclusion, eugenol avoided changes in lung mechanics, pulmonary inflammation, and alveolar collapse elicited by diesel particles. It attenuated the activation signal of caspase-3 by DEP, but apoptosis evaluated by TUNEL was avoided. Finally, it could not avoid oxidative stress as indicated by malondialdehyde.
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Chicayban LM, Zin WA, Guimarães FS. Can the Flutter Valve improve respiratory mechanics and sputum production in mechanically ventilated patients? A randomized crossover trial. Heart Lung 2011; 40:545-53. [DOI: 10.1016/j.hrtlng.2011.05.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 05/17/2011] [Accepted: 05/18/2011] [Indexed: 10/17/2022]
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Monção-Ribeiro LC, Cagido VR, Lima-Murad G, Santana PT, Riva DR, Borojevic R, Zin WA, Cavalcante MCM, Riça I, Brando-Lima AC, Takiya CM, Faffe DS, Coutinho-Silva R. Lipopolysaccharide-induced lung injury: role of P2X7 receptor. Respir Physiol Neurobiol 2011; 179:314-25. [PMID: 21982752 DOI: 10.1016/j.resp.2011.09.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 09/27/2011] [Accepted: 09/27/2011] [Indexed: 12/20/2022]
Abstract
RATIONALE P2X7 receptors have been involved in inflammatory and immunological responses, and their activation modulates pro-inflammatory cytokines production by LPS-challenged macrophages. OBJECTIVES To determine the role of P2X7R in LPS-induced acute lung injury in mice. METHODS Wild-type (C57BL/6) and P2X7 knockout mice received intratracheal injection of saline or Escherichia coli LPS (60 μg). After 24h, changes in lung mechanics were determined by the end-inflation occlusion method. Bronchoalveolar lavage was performed, and lungs were harvested for measurement of morphometry, fibers content, inflammatory cells and cytokine expression by histochemistry and immunohistochemistry. RESULTS Compared with saline, LPS increased lung mechanical parameters, mast cell, collagen and fibronectin deposition in lung parenchyma, as well as nitric oxide and lactate dehydrogenase release into bronchoalveolar fluid in wild-type, but not in P2X7R knockout mice. Alveolar collapse, lung influx of polymorphonuclear and CD14(+) cells, as well as TGF-β, MMP-2, and IL-1β release were higher in wild-type than knockout LPS-challenged mice, while MMP-9 release where similar between the two genotypes. LPS increased macrophage immunoreactivity in lung tissue in both genotypes, but macrophages were not activated in the P2X7R knockout mice. Furthermore, LPS administration increased P2X7R immunoexpression in lung parenchyma in wild-type mice, and TLR4 in both wild-type and P2X7R knockout mice. CONCLUSION P2X7 receptors are implicated in the pathophysiology of LPS-induced lung injury, modulating lung inflammatory and functional changes.
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Ferreira HC, Mazzoli-Rocha F, Momesso DP, Garcia CSNB, Carvalho GMC, Lassance-Soares RM, Prota LFM, Morales MM, Faffe DS, Carvalho AR, Rocco PRM, Zin WA. On the crucial ventilatory setting adjustment from two- to one-lung ventilation. Respir Physiol Neurobiol 2011; 179:198-204. [PMID: 21871975 DOI: 10.1016/j.resp.2011.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 08/10/2011] [Accepted: 08/12/2011] [Indexed: 11/28/2022]
Abstract
Lung mechanics, histology, oxygenation and type-III procollagen (PCIII) mRNA were studied aiming to evaluate the need to readjust ventilatory pattern when going from two- to one-lung ventilation (OLV). Wistar rats were assigned to three groups: the left lung was not ventilated while the right lung received: (1) tidal volume (V(T))=5 ml/kg and positive end-expiratory pressure (PEEP)=2 cm H(2)O (V5P2), (2) V(T)=10 ml/kg and PEEP=2 cm H(2)O (V10P2), and (3) V(T)=5 ml/kg and PEEP=5 cm H(2)O (V5P5). At 1-h ventilation, V5P2 showed hypoxemia, alveolar collapse and impaired lung function. Higher PEEP minimized these changes and prevented hypoxemia. Although high V(T) prevented hypoxemia and maintained a higher specific compliance than V5P2, a morphologically inhomogeneous parenchyma and higher PCIII expression resulted. In conclusion, the association of low V(T) and an adequate PEEP level could be useful to maintain arterial oxygenation without inducing a possible inflammatory/remodeling response.
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