ABSTRACT
OBJECTIVE(S): Reflexes that rose from mechanoreceptors in nasal cavities have extensive neuro-regulatory effects on respiratory system. Because of side specific geometry and dual innervations of the nasal mucosa, we investigated the consequences of unilateral nasal stimulations on respiratory mechanics and breathing patterns. MATERIALS AND METHODS: Unilateral nasal air-puff stimulation (30 min) in the presence of propranolol (25 mg/kg) and atropine (5 mg/kg) were applied on tracheotomized spontaneously breathing rats. Breathing rate and pattern monitored. Peak inspiratory pressure (PIP) and flow (PIF) were exploited for calculation of resistance, dynamic compliance (Cdyn), and estimation of respiratory system impedance (Zrs). RESULTS: During right-side stimulation, in propranolol (P<0.05) and atropine groups (P<0.01) PIP significantly decreased in comparison to the control group. Alternatively, it significantly increased in left-side and propranolol-left groups (P<0.05) than control group. Mean Cdyn following left-side stimulation and propranolol, revealed significant decrements (P<0.05) than control group. In the case of atropine-right and atropine-left groups, mean Cdyn had significantly decreased in comparison with atropine alone (P<0.05). Airway resistance (R) did not reveal significant difference during nasal stimulations whereas least square approximation revealed a significant side-specific frequency dependent deviation of imaginary part of impedance (X). An inverse correlation was determined for Cdyn versus frequency following right side (R=-0.76) and left side (R=-0.53) stimulations. CONCLUSION: For the reason that lower airways mechanics changed in a way independent from smooth muscle, it may be concluded from our data that unilateral nasal stimulations exert their different controls through higher regulatory centers.
ABSTRACT
The rapid identification of relevant bacterial pathogens is of utmost importance in clinical settings. The aim of this study was to test a rapid identification technique for A. baumannii strains from Tehran Hospitals and to determine the antibiotic resistance profiles of the isolates. A hundred strains of Acinetobacter spp. grown from clinical specimens were identified as A. baumannii by conventional methods. Using PCR a bla OXA-51 -like gene was detected in all A. baumannii isolates but not in other species of acinetobacter. More than half of the isolates proved resistant to a variety of antibiotics by the disk diffusion technique. The rate of resistance to gentamicin, imipenem, ampicillin-sulbactam and amikacin was determined to be 45%, 53%, 62% and 62%, respectively. Moreover, most isolates (more than 90%) showed resistance to cephalosporins. This study shows that the demonstration of the bla OXA-51-like gene is a reliable and rapid way for the presumptive identification of A. baumannii and reveals that the rate of antibiotic resistance is high in Iranian A. baumannii isolates to a variety of antibiotics.
