(1/281) Beneficial effects of raxofelast (IRFI 016), a new hydrophilic vitamin E-like antioxidant, in carrageenan-induced pleurisy.
1. Peroxynitrite is a strong oxidant that results from reaction between NO and superoxide. It has been recently proposed that peroxynitrite plays a pathogenetic role in inflammatory processes. Here we have investigated the therapeutic efficacy of raxofelast, a new hydrophilic vitamin E-like antioxidant agent, in rats subjected to carrageenan-induced pleurisy. 2. In vivo treatment with raxofelast (5, 10, 20 mg kg(-1) intraperitoneally 5 min before carrageenan) prevented in a dose dependent manner carrageenan-induced pleural exudation and polymorphonuclear migration in rats subjected to carrageenan-induced pleurisy. Lung myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels, as well as histological organ injury were significantly reduced by raxofelast. 3. Immunohistochemical analysis for nitrotyrosine, a footprint of peroxynitrite, revealed a positive staining in lungs from carrageenan-treated rats. No positive nitrotyrosine staining was found in the lungs of the carrageenan-treated rats, which received raxofelast (20 mg kg 1) treatment. 4. Furthermore, in vivo raxofelast (5, 10, 20 mg kg(-1)) treatment significantly reduced peroxynitrite formation as measured by the oxidation of the fluorescent dihydrorhodamine 123, prevented the appearance of DNA damage, the decrease in mitochondrial respiration and partially restored the cellular level of NAD+ in ex vivo macrophages harvested from the pleural cavity of rats subjected to carrageenan-induced pleurisy. 5. In conclusion, our study demonstrates that raxofelast, a new hydrophilic vitamin E-like antioxidant agent, exerts multiple protective effects in carrageenan-induced acute inflammation. (+info)
(2/281) Bronchial carcinoma in patients with pre-existing unilateral lung disease.
Forty-six cases of primary bronchogenic carcinoma occurring in patients with other unilateral pleuropulmonary diseases were studied. In 37 cases (80-4%) carcinoma developed in the previously healthy lung. All but one squamous-cell carcinoma and all of five undifferentiated small-cell carcinomas developed in the previously healthy lung while 7 of 15 adenocarcinomas were in the lung with impaired ventilation. It is suggested that the bronchial epithelium of the healthy lung is more exposed to exogenous carcinogens than that of the diseased, underventilated lung, resulting in a higher risk of development of squamous-cell and undifferentiated small-cell carcinoma. (+info)
(3/281) Effect of a novel non-steroidal anti-inflammatory drug (M-5011) on cytokine levels in rats with monosodium urate crystal- induced pleurisy.
We evaluated the effects of a new non-steroidal anti-inflammatory drug (NSAID), d-2-[4-(3-methyl-2-thienyl)phenyl]propionic acid (M-5011), and indomethacin on the production of arachidonate metabolites and pro-inflammatory cytokines in male Sprague-Dawley rats with monosodium urate crystal (MSU)-induced pleurisy. Levels of tumor necrosis factor (TNF), interleukin (IL)-1 and IL-6 in the pleural exudate were determined by biological assays, while prostaglandin E2 (PGE2), leukotriene B4 (LTB4) and cytokine-induced chemoattractant-1 (CINC-1) levels were quantified by enzyme immunoassays. Orally administered M-5011 (5 mg/kg) decreased the pleural exudate volume at 3 and 4 hr after MSU injection. Indomethacin (10 mg/kg) decreased the volume at 3-5 hr. These drugs reduced the number of leukocytes in the pleural cavity at 6 hr. Both NSAIDs also reduced the content of PGE2 in the exudate without affecting LTB4 levels. Increased productions of both IL-6 and CINC-1 in the exudate were reduced by pretreatment with M-5011 or indomethacin, and TNF levels in the exudate were increased by pretreatment of these drugs. Thus, M-5011 inhibits the production of both IL-6 and CINC-1 at lower doses than those of indomethacin, and the inhibitory effect of M-5011 on CINC-1, but not IL-6, may partly contribute to the inhibition of leukocyte infiltration in rats with MSU-induced pleurisy. (+info)
(4/281) Bilateral pleuritis caused by Legionella micdadei.
A 58-year-old woman was hospitalized because of progressive respiratory distress. She had a history of myasthenia gravis and invasive thymoma. After thymectomy, she had been administered oral prednisolone and intrathoracic anti-cancer drugs postoperatively. Her chest radiograph revealed bilateral pleural effusions. Legionella micdadei (L. micdadei) was isolated from the pleural effusions, and she was diagnosed as pleuritis caused by L. micdadei. She died despite intensive therapy with mechanical ventilation, drainage tube in the chest and intravenous erythromycin. Although only two cases of Legionellosis caused by L. micdadei have been reported in Japan, clinicians should be aware of L. micdadei as one of the candidates for infection in immunosuppressed hosts. (+info)
(5/281) Suppressive effect of distinct bradykinin B2 receptor antagonist on allergen-evoked exudation and leukocyte infiltration in sensitized rats.
1. Bradykinin is suggested to play a role in the pathophysiology of several acute and chronic diseases, including allergic disorders such as asthma. In the present study, we have investigated the importance of bradykinin in mediating allergic inflammation in rats. 2. To this end we have tested the effects of the B2 receptor antagonists Hoe 140, FR173657 or FR172357 on the pleural inflammatory response triggered by intrapleural (i.pl.) injection of allergen (ovalbumin, 12 microg cavity(-1)) in 14 day-actively sensitized Wistar rats. Analysis of the pleural fluid effluent revealed a sequence of mast cell-dependent inflammatory events, including early protein exudation and neutrophilia and late pleural eosinophil influx. 3. Local treatment with Hoe 140 (0.1 and 1 microg cavity(-1)), FR173657 (1 and 10 microg cavity(-1)) or FR172357 (1 and 10 microg cavity(-1)) inhibited dose-dependently allergen-induced mast cell activation with impairment of pleural plasma leakage, neutrophil accumulation and late eosinophil influx. 4. Moreover, the B2 receptor antagonists also dose-dependently inhibited the allergic like inflammatory pleurisy triggered by bradykinin (50 microg cavity(-1)), which is characterized by acute mast cell degranulation, protein leakage and pleural eosinophil infiltration. 5. Taken together, our findings provide substantial evidence to suggest that bradykinin acting on its B2 receptors play a critical role in mediating allergic mast cell-dependent inflammation in rats, and suggest that B2 receptor antagonists may be useful therapeutically to control allergic dysfunction. (+info)
(6/281) Bradykinin down-regulates LPS-induced eosinophil accumulation in the pleural cavity of mice through type 2-kinin receptor activation: a role for prostaglandins.
1. The role of both exogenously administered and endogenously generated bradykinin (BK) on LPS-induced eosinophil accumulation in the mice pleural cavity was investigated by means of treatment with BK selective receptor agonists/antagonists and captopril. 2. Intrathoracic (i.t.) injection of LPS (250 ng cavity(-1)) induced eosinophil influx at 24 h as previously described (Bozza et al., 1993). Pretreatment with the B1 receptor antagonist des-Arg9-[leu-8]BK (0.025 and 0.25 nmol cavity(-1)) showed no effect on this phenomenon, whereas pretreatment with the B2 receptor antagonists, NPC 17731 (0.025 and 0.25 nmol cavity(-1)) or HOE 140 (2.5 nmol cavity(-1)), increased LPS-induced eosinophil influx. Accordingly, pretreatment with captopril at 10 mg kg(-1) i.p., inhibited eosinophil infiltration induced by LPS in the pleural cavity, suggesting that endogenous BK is down-regulating LPS-induced eosinophil accumulation. 3. BK administered at 15 and 25 nmol cavity(-1), i.t. or i.p. also inhibited LPS-induced eosinophil accumulation. BK alone had no effect on the basal number of leucocytes in the pleural or peritoneal cavity in doses up to 25 nmol cavity(-1). Nevertheless, when injected at doses of 50 and 100 nmol cavity(-1) BK induced leucocyte influx characterized by neutrophil and eosinophil accumulation at 24 h. 4. Similarly to what was observed with BK, a specific B2 receptor agonist, Tyr8BK, administered at 0.25 nmol cavity(-1) i.p., significantly inhibited the eosinophil influx induced by LPS. 5. The mechanism by which B2 receptor agonists inhibit LPS-induced eosinophil accumulation was investigated by pretreating the animals with indomethacin or a selective cyclooxygenase-2 inhibitor, NS-398. Pretreatment with either indomethacin or NS-398 had no effect on eosinophil influx induced by LPS alone, but those drugs were able to restore the LPS-induced eosinophil influx in Tyr8BK (0.25 nmol cavity(-1)) injected mice. 6. In conclusion, endogenously generated bradykinin seems to modulate, through activation of B2 receptors, eosinphil accumulation induced by LPS via a mechanism dependent on prostanoid synthesis. (+info)
(7/281) Role of IL-6 in the pleurisy and lung injury caused by carrageenan.
In the present study we used IL-6 knockout mice (IL-6KO) to evaluate the role of IL-6 in the inflammatory response caused by injection of carrageenan into the pleural space. Compared with carrageenan-treated IL-6 wild-type (IL-6WT) mice, carrageenan-treated IL-6KO mice exhibited a reduced degree of pleural exudation and polymorphonuclear cell migration. Lung myeloperoxidase activity and lipid peroxidation were significantly reduced in IL-6KO mice compared with those in IL-6WT mice treated with carrageenan. Immunohistochemical analysis for nitrotyrosine and poly(A)DP-ribose polymerase revealed a positive staining in lungs from carrageenan-treated IL-6WT mice. No positive staining for nitrotyrosine or PARS was found in the lungs of the carrageenan-treated IL-6KO mice. Staining of lung tissue sections obtained from carrageenan-treated IL-6WT mice with an anti-cyclo-oxygenase-2 Ab showed a diffuse staining of the inflamed tissue. Furthermore, expression of inducible nitric oxide synthase was found mainly in the macrophages of the inflamed lungs from carrageenan-treated IL-6WT mice. The intensity and degree of the staining for cyclo-oxygenase-2 and inducible nitric oxide synthase were markedly reduced in tissue sections obtained from carrageenan-treated IL-6KO mice. Most notably, the degree of lung injury caused by carrageenan was also reduced in IL-6KO mice. Treatment of IL-6WT mice with anti-IL-6 (5 microg/day/mouse at 24 and 1 h before carrageenan treatment) also significantly attenuated all the above indicators of lung inflammation. Taken together, our results clearly demonstrate that IL-6KO mice are more resistant to the acute inflammation of the lung caused by carrageenan injection into the pleural space than the corresponding WT mice. (+info)
(8/281) The protective role of endogenous melatonin in carrageenan-induced pleurisy in the rat.
Peroxynitrite, a potent cytotoxic oxidant formed by the reaction of nitric oxide (NO) with the superoxide anion, was recently proposed to play a major pathogenic role in the inflammatory process. Here we have investigated the effects of endogenous melatonin, a known scavenger of peroxynitrite, in rats subjected to carrageenan-induced pleurisy. Endogenous melatonin was depleted in rats maintained on 24 h light cycle for 1 wk. In vivo depletion of endogenous melatonin enhanced the carrageenan-induced degree of pleural exudation and polymorphonuclear leukocyte migration in rats subjected to carrageenan-induced pleurisy. Lung myeloperoxidase activity and lipid peroxidation were significantly increased in melatonin-deprived rats. However, the inducible NO synthase in lung samples was unaffected by melatonin depletion. Immunohistochemical analysis for nitrotyrosine revealed a positive staining in lungs from carrageenan-treated rats that was markedly enhanced in melatonin-deprived rats. Furthermore, melatonin depletion significantly increased peroxynitrite formation as measured by the oxidation of the fluorescent dye dihydrorhodamine 123, enhanced DNA damage and the decrease in mitochondrial respiration and reduced the cellular levels of NAD+ in macrophages harvested from the pleural cavity of rats subjected to carrageenan-induced pleurisy. In vivo treatment with exogenous melatonin (15 mg/kg intraperitoneal) significantly reversed the effects of melatonin depletion. Thus, endogenous melatonin plays an important protective role against carrageenan-induced local inflammation. (+info)