ROGERIO PAZETTI
Projetos de Pesquisa
Unidades Organizacionais
LIM/61 - Laboratório de Pesquisa em Cirurgia Torácica, Hospital das Clínicas, Faculdade de Medicina
2 resultados
Resultados de Busca
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- Pulmonary emphysema induced by methylphenidate: experimental study(2015) RAPELLO, Gabriel Victor Guimaraes; ANTONIOLLI, Andreia; PEREIRA, Daniel Martins; FACCO, Gilberto; PEGO-FERNANDES, Paulo Manuel; PAZETTI, RogerioCONTEXT AND OBJECTIVE: Methylphenidate is the most widely used drug for treating attention deficit hyperactivity disorder. However, it has important side effects, such as abdominal pain, insomnia, anorexia and loss of appetite, and also some cases of early severe emphysema after drug abuse have been reported. Our aim was to investigate the development of pulmonary emphysema in rats that were subjected to different doses of methylphenidate. DESIGN AND SETTING: Experimental study carried out at the laboratory of a public university. METHODS: Eighteen male Wistar rats were divided into three groups: control (0.9% saline solution); MP 0.8 (methylphenidate, 0.8 mg/kg); MP 1.2 (methylphenidate, 1.2 mg/kg). After 90 days of daily gavage, the animals were sacrificed and lung tissue samples were prepared for analysis on the mean alveolar diameter (Lm). RESULTS: The Lm was greater in MP 0.8 (47.91 +/- 3.13; P < 0.01) and MP 1.2 (46.36 +/- 4.39; P < 0.05) than in the control group (40.00 +/- 3.48). CONCLUSION: Methylphenidate caused an increase in the alveolar diameter of rats, which was compatible with human pulmonary emphysema.
- Respiratory parameters have different patterns in imposed-inspiration and imposed-expiration within a closed pneumatic circuit in rats(2015) AOKI, F. G.; VALENGA, M. H.; RODRIGUES, T. G.; CARDOSO, P. F. G.; PAZETTI, R.; MORIYA, H. T.Computer-controlled research ventilators for small animals (SAV) are often used to assess the respiratory mechanics' parameters such as resistance and elastance of the respiratory system in animal models of disease. In commercially available SAVs, it is common to obtain such parameters with the forced oscillation of a given volume of air into respiratory system with a quasi-sinusoidal pattern in a closed pneumatic circuit (i.e. both the injection and the removal of gas during the piston movement). We hypothesized that obtaining the respiratory mechanical parameters with the linear single-compartment model (LSCM) during the forced inspiration and forced expiration (when calculated together) is not sufficient to explain the physiology of the respiratory system exposed to high doses of bronchial agonist. In order to verify this, male Wistar rats (n = 5) were anesthetized, orotracheally intubated, mechanically ventilated at 90bpm (or 1.5Hz) with a tidal volume of 10mL/kg, and a positive end-expiratory pressure (PEEP) was set at 3cmH(2)O. The ventilation was performed in a commercial mechanical ventilator (flexiVent, SCIREQ Inc., Canada) and the animals were infused with a saline solution (PBS), followed by 3 increasing doses (3, 30 and 300mg/mL) of the bronchial agonist methacholine (MCh). Respiratory parameters were calculated by the LSCM. Pressure and volume data, calibrated and corrected by a proprietary software, were analyzed using a computational routine. The full quasisinusoidal signal data was compared to inlet and outlet of air from the lungs separately. The data obtained showed that the difference among the three signals (i.e. whole signal, imposed-inspiration, and imposed-expiration) is pronounced at the higher dose (MCh 300mg/mL). Data from imposed-inspiration alone seem to better reflect the respiratory mechanics when a large dose of bronchial agonist is used.