139 research outputs found
Hyperreactivity and bronchial obstruction.
The main obstructive components in bronchial asthma and chronic obstructive pulmonary disease (COPD) are discussed. It is underscored that bronchospasm plays a significant role also in COPD, and that it merits specific treatment (beta 2-stimulants, antimuscarinics, theophylline) even when, in some cases, obstruction appears to be 'irreversible'. The majority of COPD patients react positively, although to a lower degree than asthmatics, not only to chemical agents (histamine, methacholine), but also to 'osmotic' stimuli, such as ultrasonically nebulized distilled water. Geometric factors seem to be in part responsible for the anomalous response. Considering the potent antireactive activity of bronchodilators (beta 2-stimulants in particular), this finding is a further indication for a regular bronchodilator treatment in COPD. Whether such a therapy serves also to improve the prognosis of COPD in the long run has not yet been established
Protective effect of furosemide combined with non-steroidal anti-inflammatory drugs administered by inhalation route on guinea-pigs anaphylaxis model
The exposure of ovalbumin sensitized guinea-pig to an areosol of the specific antigen causes a respiratory crisis in approximately 100 s (dispnoea time) associated with a substantial increase in blood concentration of both histamine (from 27.5 +/- 1.8 ng/ml to 1570 +/- 26 ng/ml; n = 8) and thromboxane B2 (TXB2, from 0.52 +/- 0.03 ng/ml to 18.1 +/- 0.6 ng/ml; n = 8). The aerosol treatment of the animals (20 min) with furosemide (CAS 54-31-9, frusemide, FRU), nimesulide (CAS 51803-78-2, NIM), acetylsalicylic acid (CAS 50-78-2, ASA) and indometacin (CAS 53-86-1, INDO) at the concentrations of 1-3-10 and 30 mg/ml, before ovalbumin challenge, brought about an attenuation of anaphylactic response. The rank order of potency for the prolongation of dyspnoea time was FRU > NIM > ASA > INDO. In these experiments blood evaluation performed at the peak of the dyspnoea time for histamine concentration in the treated animals indicated that whereas FRU (ED25 = 2.14 mg/ml (1.97-2.38) and NIM (ED25 = 2.74 mg/ml (2.37-3.19)) were equiactive in reducing the release of histamine, ASA and INDO were devoid of this activity. On the contrary, the results obtained with ASA and INDO indicated a greater intrinsic activity in antagonizing TXB2 formation than that shown by the log-dose response curves of NIM and FRU. In another series of experiments the interaction of FRU with the other anti-inflammatory drugs in protecting guinea-pig from immune bronchoconstriction has been evaluated using the combination of two equiactive doses. The mixture considered were FRU+NIM, FRU+INDO and FRU+ASA. The results obtained indicated that FRU interacts positively with the three non-steroidal anti-inflammatory drugs in delaying the onset of the dyspnoeic crisis in guinea-pig. However, when FRU was combined with NIM the gain obtained (209%) appeared superior to that reached when FRU was combined with ASA (180%) or INDO (126%). Taken together these results suggest that non-steroidal anti-inflammatory compounds given by aerosol may represent a valid pharmacological intervention in protecting guinea-pig from anaphylactic bronchoconstriction
Minimum-fuel Engine On/Off Control for the Energy Management of a Hybrid Electric Vehicle via Iterative Linear Programming
In this paper we present models and optimization algorithms to rapidly compute the fuel-optimal energy management strategies of a hybrid electric powertrain for a given driving cycle. Specifically, we first identify a mixed-integer model of the system, including the engine on/off signal. Thereafter, by carefully relaxing the fuel-optimal control problem to a linear program, we devise an iterative algorithm to rapidly compute the minimum-fuel energy management strategies. We validate our approach by comparing its solution with the globally optimal one obtained solving the mixed-integer linear problem and demonstrate its effectiveness by assessing the impact of different battery charge targets on the achievable fuel consumption. Numerical results show that the proposed algorithm can assess fuel-optimal control strategies in a few seconds, paving the way for extensive parameter studies and real-time implementations
Different effects of inhaled aspirinlike drugs on allergen-induced early and late asthmatic responses.
Little Is known about the anti-asthmatic effects of powerful anti-inflammatory agents such as aspirin-like drugs. We compared the effects of two aspirin-like drugs with different pharmacologic activities, sodium salicylate (SSA) and indomethacin, with the effect of lysine acetylsalicylate (LASA), inhaled 30 min before challenge, on the early and the late asthmatic response induced by a single dose of allergen causing a 25% decrease in FEV1 In a preliminary challenge. Inhaled SSA partially prevented both the early and late response, providing a protection with respect to placebo of 22 +/- 6% in the early phase and 23 +/- 9% in the late phase of the response. These values were lower (but not significantly) than those of LASA (41 +/- 9% and 39 +/- 11%, respectively). In a second group of patients, indomethacin failed to affect the early response, while LASA provided a protection of 31 +/- 7%. However, these two drugs were equally effective in reducing the late response (44 +/- 18% and 39 +/- 17% protection for LASA and indomethacin, respectively), In subjects with an early response, despite being ineffective in preventing allergen-induced bronchoconstriction, indomethacin blocked the allergen-induced increase in bronchial hyperresponsiveness measured 2 h after challenge. We conclude that inhaled salicylates, but not indomethacin, exert a protective activity against the early allergic response. This difference is nor. explained by the different pattern of cyclooxygenase inhibitory activity of these drugs
Antianaphylactic and antihistaminic activity of the non-steroidal anti-inflammatory compound nimesulide in guinea-pig
Nimesulide (4-nitro-2-phenoxymethane sulfonanilide, Aulin, Mesulid) is a non-steroidal anti-inflammatory compound which shows antihistaminic activity and inhibits the immune release of histamine. The antihistaminic activity of this compound is specific for H1-receptor and has been demonstrated on isolated strips of guinea-pig trachea and on histamine-induced multiphasic inotropic response in left atria of guinea pig electrically driven. The effect of nimesulide is of non competitive type and, at the concentration of 1 x 10(-5) mol/l, is nearly 2 time less potent than pyrilamine (mepyramine) at 1 x 10(-6) mol/l. Nimesulide (1.6 mumol/kg i.v.) inhibits both bronchoconstriction (69%) and TXB2 formation (93%) induced by histamine (0.05 mumol/kg i.v.) in anaesthetized guinea-pigs. In contrast indomethacin (1.6 mumol/kg i.v.) decreases the generation of TXB2 (89%) without affecting the enhancement in tracheal insufflation pressure induced by histamine. In actively sensitized guinea-pigs both nimesulide and indomethacin protect the animals from deadly anaphylactic crisis. The rise in tracheal pressure induced by the antigenic challenge is inhibited of 80% and 63% respectively by nimesulide and indomethacin (6.4 mumol/kg i.v.). At this dose the two compounds reduced of 90% approximately the immunological release of TXB2 in the circulation. The release of histamine, induced by the anaphylactic reaction caused in perfused lungs obtained from actively sensitized guinea-pigs, is lessened by nimesulide (EC50 = 3.06; fid. lim. 2.59-3.63 mumol/l) and potentiated by indomethacin (EC50 = 0.89; fid. lim. 0.67-1.17 mumol/l).(ABSTRACT TRUNCATED AT 250 WORDS
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