Marco Aurélio dos Santos Silva

Time course of inflammation, oxidative stress and tissue damage induced by hyperoxia in mouse lungs

In this study our aim was to investigate the time courses of inflammation, oxidative stress and tissue damage after hyperoxia in the mouse lung. Groups of BALB/c mice were exposed to 100% oxygen in a chamber for 12, 24 or 48 h. The controls were subjected to normoxia. The results showed that IL‐6 increased progressively after 12 (P < 0.001) and 24 h (P < 0.001) of hyperoxia with a reduction at 48 h (P < 0.01), whereas TNF‐α increased after 24 (P < 0.001) and 48 h (P < 0.001). The number of macrophages increased after 24 h (P < 0.001), whereas the number of neutrophils increased after 24 h (P < 0.01) and 48 h (P < 0.001). Superoxide dismutase activity decreased in all groups exposed to hyperoxia (P < 0.01). Catalase activity increased only at 48 h (P < 0.001). The reduced glutathione/oxidized glutathione ratio decreased after 12 h (P < 0.01) and 24 h (P < 0.05). Histological evidence of lung injury was observed at 24 and 48 h. This study shows that hyperoxia initially causes an inflammatory response at 12 h, resulting in inflammation associated with the oxidative response at 24 h and culminating in histological damage at 48 h. Knowledge of the time course of inflammation and oxidative stress prior to histological evidence of acute lung injury can improve the safety of oxygen therapy in patients.

l-NAME and l-arginine differentially ameliorate cigarette smoke-induced emphysema in mice

Nitric oxide (NO) represents one of the most important intra- and extracellular mediators and takes part in both biologic and pathologic processes. This study aimed to verify the treatment with an NO inhibitor and an NO substrate in pulmonary emphysema induced by cigarette smoke (CS) in a murine model. We compared N-acetylcysteine (NAC), a precursor of glutathione, to G-nitro-L-arginine-methyl ester or L-NAME (LN), which is an NO inhibitor, and to l-arginine (LA), which is a substrate for NO formation. Mice were divided into several groups: control, CS, CS + LN, CS + LA, and CS + NAC. Control and CS groups were treated daily with a vehicle, while CS + LN, CS + LA, and CS + NAC groups were treated daily with LN (60 mg/kg), LA (120 mg/kg) and NAC (200 mg/kg), respectively. The bronchoalveolar lavage was analyzed and the lungs were removed for histological and biochemical analysis. CS increases neutrophil number. Neutrophil number was lowest in CS + LN, followed by CS + LA. The lungs of CS + LN, CS + LA and CS + NAC mice were protected compared to the lungs of CS mice, but not equal to the quality of lungs in control mice. The CS group also exhibited increased oxidative stress, which was also present in the CS + LN group and to a lesser extent in the CS + LA group. Tissue inhibitor of metalloproteinase 1 and 2 increased in the CS + LN group and to a lesser extent in the CS + LA group relative to the control group. These results suggest that LN and LA treatment protected the mouse lung from CS. However, NAC treatment was more than LN and LA. We suggest that the protection conferred by LN treatment requires a balance between proteases and antiproteases, and that protection conferred by LA treatment involves the balance between oxidants and antioxidants.

Endotoxin-induced acute lung injury is dependent upon oxidative response

The aim of the present study was to investigate the involvement of oxidative stress in acute lung injury (ALI) induced by lipopolysaccharide (LPS) and its effects upon cell structure, function and inflammation. In total, 108 male C57BL/6 mice were divided into seven groups: CTR Group (50 µL of saline) administered intratracheally (i.t.), LPS 6 h (10 µg of LPS − i.t.), LPS 12 h (10 µg of LPS − i.t.), LPS 24 h (10 µg of LPS − i.t.), LPS 48 h (10 µg of LPS − i.t.), LPS 24 h (10 µg − i.t.) + NAC 40 mg/kg (gavage) and 24 h LPS (10 µg − i.t.) + NAC 100 mg/kg (gavage). The antioxidant treatment protected the lungs from stress in the first 12 h, but significant oxidative stress induction was observed at the 24-hour time point, and, after 48 h, there was no protection exerted by the antioxidant treatment. NAC (N-acetylcysteine) reversed the elastance parameters, and ΔP1 and ΔP2 compared with 24 h LPS alone. NAC reduced the number of inflammatory cells in histology analysis when compared with the 24 h LPS alone-treated group. NAC also inhibited the transcription of NFκB, IL-6, TNF-α and COX2 usually induced by LPS. Our results suggest that oxidative stress plays an important role in structural, functional and inflammatory responses in the ALI model.

Acromial Morphometric Analysis Using Imaging Software

El objetivo de este estudio fue medir con precision la morfologia acromial para describir los patrones anatomicos de sus subtipos y llevar a cabo un estudio de la literatura sobre las relaciones entre los subtipos morfologicos y las enfermedades relacionadas. Tomamos fotografias de la escapula del Instituto de Anatomia de la Universidad Sombra Severino, y se analizaron las imagenes con el Software Image-J®. El angulo acromial medio fue de 139,23 ± 2,781°, no habiendo diferencias significativas entre los lados derecho e izquierdo. De observo una correlacion positiva entre el angulo acromial y el angulo de la columna vertebral de la escapula. La correlacion mencionada anteriormente, juega un papel importante en los trastornos de la inflamacion del hombro, especialmente el sindrome, lo cual refuerza la importancia de los estudios de la morfologia acromial.

Genomic stability and telomere regulation in skeletal muscle tissue

Muscle injuries are common, especially in sports and cumulative trauma disorder, and their repair is influenced by free radical formation, which causes damages in lipids, proteins and DNA. Oxidative DNA damages are repaired by base excision repair and nucleotide excision repair, ensuring telomeric and genomic stability. There are few studies on this topic in skeletal muscle cells. This review focuses on base excision repair and nucleotide excision repair, telomere regulation and how telomeric stabilization influences healthy muscle, injured muscle, exercise, and its relationship with aging. In skeletal muscle, genomic stabilization and telomere regulation seem to play an important role in tissue health, influencing muscle injury repair. Thus, therapies targeting mechanisms of DNA repair and telomeric regulation could be new approaches for improving repair and prevention of skeletal muscle injuries in young and old people.

Challenges of Airway Management in EmergencySituations: A Literature Review

The management of the airways in emergency situations is considered one of the main life-saving acts [1]. According to Advanced Trauma Life Support recommendations for the management of patients with life-threatening injuries, airway protection is the first intervention [2]. Endotracheal intubation is the technique of choice because it is a fast, more frequently successful procedure and allows the use of a larger tube [1,2]. They are indications for endotracheal intubation and emergency: maintenance of airway permeability, respiratory failure unrelated to upper airway obstruction, decreased risk of aspiration of gastric contents [2]. Evidence corroborated the findings that the efficacy of bag-valve-mask use in emergencies, most emergency intubations occur in situations of cardiorespiratory arrest, the difference in the development of pneumonia due to invasive airway management in a pre-operative environment -hospital and hospital are not significant and the combination of ketamine and propofol (known as cetofol) is an alternative for etomidate in sedation for maintaining hemodynamic stability [2-11]. The objective of this study is to perform a review on the management of the airways in emergency situations.

Influência do posicionamento dos membros superiores sobre parâmetros ventilatórios em indivíduos adultos

INTRODUCTION: Pulmonary ventilation depends on the integrity of the chest wall. The positioning of the chest wall and/or the disorders of ventilatory muscles decrease the lung volume and capacity, the flow of airway pressure and inspiratory and expiratory pressures. The positioning of the upper limbs interferes with the dynamics of the chest. OBJECTIVES: To determine the effect of positioning of the arms with the shoulder 90o abduction and external rotation associated with elbow flexion to 90o on the pulmonary ventilatory function. METHODS: The subjects underwent Respiratory Questionnaire suggested by the American Thoracic Society - Division of Lung Diseases (ATS-DLD) and the individual records to search for clinical assessment of ventilatory lung function. RESULTS: We found out that the minute volume and tidal volume in healthy subjects in post-position increased when compared to the situation of pre-positioning from 9.46 ± 1.15 L/min. to 11.89 ± 1.54 L/min. and from 565.8 ± 83.84 ml to 752.4 ± 105.5 mL, respectively. CONCLUSION: The placement of members can be prioritized before lung reexpansion techniques. Pulmonary rehabilitation programs in general may include the correct positioning of the upper limbs, as this represents an advantage to muscles that act on the rib cage, improving the performance of ventilation.