Effect of platelet activating factor (PAF) on pulmonary circulation in isolated rabbit lung.

Platelet activating factor (PAF) has been implicated in the pathophysiology of acute lung injury. The aim of this work is to study the effect of PAF on isolated and perfused rabbit lungs with blood and with a blood-free solution. 24 isolated and perfused rabbit lungs have been used: 8 control preparations (CP), 4 vehicles preparations (VP), 8 PAF preparations (PP) to which we administered PAF (1 microg/Kg of rabbit weight) and 4 acellular preparations (AP) with the same dose of PAF as in PP but dissolved in BSA-Krebs buffer solution. In the preparations pulmonary artery pressure (Ppa), airway pressure (Paw), left atria pressure (Pla) and fluid filtration rate (FFR) were registered. Ppa resulted in a significant difference in AP vs PP, with a value of 21 cm of water (CI 95%: 12-26) vs 205.1 cm of water (CI 95%: 141.3 - 271) respectively. A increase in FFR was observed in PP but it did not occur in AP, the difference being statistically significant: 5.515 g/min (CI 95 %: 2.425 - 8.865) vs 0.049 g/min (CI 95%: 0.008 - 0.32) respectively. Paw was statistically different in PP vs AP, with a value of 14.3 cm of water (CI 95%: 11.57 - 16.7) vs 8.5 cm of water (CI 95%: 8-9) respectively. These results suggest that PAF does not have a direct effect on the endothelium or smooth muscle in the production of lung edema.

[Autoimmune chronic hepatitis: clinico-pathologic spectrum in 7 cases]. / Hepatitis crónica autoinmune: espectro clínico pathológico en 7 casos.

Autoimmune chronic active hepatitis (ACAH) is an infrequent modality of chronic hepatitis (CH) with clinical and laboratory findings of an autoimmune disorder. Clinical and pathological findings of 7 cases are presented; all were females with ages between 7 and 24 years. Main symptoms and signs were weight loss, malaise, arthralgias, fever, menstrual disturbances, hepatosplenomegaly, jaundice ascites and esophageal varices. Aminotransferases were elevated in all cases, and bilirubin, alkaline phosphatase and gammaglobulins were found to be raised in six. Antinuclear antibodies were positive in 5 cases, smooth muscle antibodies in 3, and antimitochondrial antibodies were detected in one. Morphological changes were those of chronic active hepatitis with variable degrees of fibrosis. Plasma cells were conspicuous. All patients received steroid treatment (Prednisone). It is concluded that the diagnosis of ACAH can be based on clinical and immunological criteria provided other causes of CH such as viral hepatitis, are ruled out.

Effect of Fenoterol on PAF-induced lung edema in isolated and perfused rabbit lungs.

We have studied the effects of fenoterol on PAF-induced response in pulmonary circulation. We used 28 isolated and perfused rabbit lungs preparations: eight control preparations (CP), four vehicles preparations (VP), eight PAF preparations (PP) with two doses of PAF, one called low dose (LD = 0.5 microg/kg of weight) and the other high dose (HD = 1 microg/kg of weight) and eight Fenoterol preparations (FP) which we administered 0.05 mg of Fenoterol for 15 min, followed by a LD and HD of PAF. FP prevented elevation of pulmonary artery pressure (Ppa) as compared to PP, at LD of PAF: 12.615 (CI 95%: 8.57-20.885) versus 83.705 (CI 95%: 50.55-114.3) cm of water; and at HD of PAF: 19.38 (CI 95%: 11.235-28.94) versus 205.1 (CI 95%: 141.3-271) cm of water respectively. FP prevented the increase in fluid filtration rate (FFR) observed in PP at both doses of PAF LD: 0.765 (CI 95%: 0.07-3.385) versus 0.01 (CI 95%: -0.05-0.005) g/min; HD: 5.515 (CI 95%: 2.425-8.865) versus 0.03 (CI 95%: 0-0.33) g/min. Our results suggest that PAF has a vasoconstrictor effect that produces lung edema and this effect is inhibited by fenoterol.

Effect of dopamine on platelet activating factor induced-pulmonary edema in isolated and perfused rabbit lungs.

The effect of dopamine over pulmonary edema induced by PAF was studied. Thirty preparations of rabbit lungs were used: six control preparations (CP), six PAF preparations (PP) in which we injected a dose of 1 microg/kg of rabbit weight and eighteen dopamine preparations (DAP) divided in three groups of six pretreated with a dose of 1-5 (dopaminergic range), 10-20 (Beta range) and 20-30 ug/kg/min (Alpha range) of dopamine, respectively for 30 min, followed by an injection of PAF as in the PP. DAP at Beta and Alpha-adrenergic range decreased pulmonary artery pressure (Pap) as compared to CP, with values of 11.66 (CI 95%: 10.83-12.48), 11.66 (CI 95%: 9.87-13.44) versus 17.12 (CI 95%: 16.12-18.11) cm of water, respectively. DAP in Beta and Alpha-adrenergic range prevented Pap increment as compared to PP, with values of 17.16 (CI 95%: 16.37-17.94), 17.5 (CI 95%: 14.93-20.06) versus 84 cm of water (CI 95%: 71.41-96.58), respectively. Dopamine, at its three ranges inhibited the augmentation of the fluid filtration rate observed in PP with values of 1.01 (CI 95%: 0.77-1.24), 0.03 (CI 95%: 0.01-0.04) and 0.02 g/min (CI 95%: -0.0004-0.03) versus 2.13 g/min (CI 95%: 1.56-2.69), respectively. We concluded that dopamine has a vasodilator effect on Pap and exerts an inhibiting action over PAF effects in pulmonary circulation. Such effects seem to be mainly mediated by Beta-receptors, rather than by dopaminergic receptors.

Effect of hydrocortisone on platelet activating factor induced lung edema in isolated rabbit lungs.

The effect of hydrocortisone on platelet activating factor (PAF)-induced pulmonary edema is studied. Thirty four isolated and perfused rabbit lung preparations were used: eight control preparations, eight PAF preparations with two doses of PAF called low dose (LD = 0.5 microg/kg of rabbit weight) and high dose (HD = 1 microg/kg of rabbit weight). Eighteen preparations divided in three groups of six were pretreated with doses of 20, 200 and 2000 mg of hydrocortisone and later given the same doses of PAF as described above. Hydrocortisone significantly decreased (P < 0.05) the effect of PAF LD over the pulmonary arterial pressure (Ppa) in the 200 and 2000 mg groups (58 and 89% decrease, respectively) and it significantly decreased (P < 0.05) the effect of PAF HD over Ppa in all hydrocortisone pretreated groups (48, 70 and 96% decrease, respectively). Fluid filtration rate (FFR) increases mediated by PAF HD were significantly inhibited (P < 0.05) in the 200 and 2000 mg groups (64 and 96% decrease, respectively). We conclude that hydrocortisone inhibits the effect of PAF over the pulmonary circulation.

MEDCARIB Evaluation of performance indices for broiler raised in conventional versus tunnel-ventilated houses and the cost effectiveness of the two types of housing in Barbados.

Retrospective data from 18 tunnel-ventilated and 41 conventional houses in Barbados were evaluated in order to compare the effects of the two types of housing using the following indices: feed conversion ratio at 1500 grammes (FCR 1500), European Production Efficiency Factor (EPEF), and net income per bird (NIPB). The data were obtained from the records of 200 and 282 grow-outs for tunnel-ventilated and conventional houses, respectively. The effects of season of placement and month of placement on the above performance variables were also evaluated. The analyses revealed that the performance variables NIPB, EPEF, and FCR 1500 were superior for tunnel -ventilated housing (P=0.02, 0.0001 respectively); were less variable from month to month for tunnel- ventilated housing; and except for NIPB, were better when birds were placed during the dry season (P=0.08, 0.0005 and 0.007 respectively). Financial anlaysis also showed that tunnel -ventilated house was more profitable venture than the conventional house. The net profit margin (15.38vs 3.59%) net profit per kg, (0.51 vs 0.12 BDS$, (BDS$1.00~ US $0.50)), and net profit per m squared (94.83vs13.13BDS$) were also higher for the tunnel-ventilated house.

MEDCARIB Evaluation of performance indices for broiler raised in conventional versus tunnel-ventilated houses and the cost effectiveness of the two types of housing in Barbados.

Retrospective data from 18 tunnel-ventilated and 41 conventional houses in Barbados were evaluated in order to compare the effects of the two types of housing using the following indices: feed conversion ratio at 1500 grammes (FCR 1500), European Production Efficiency Factor (EPEF), and net income per bird (NIPB). The data were obtained from the records of 200 and 282 grow-outs for tunnel-ventilated and conventional houses, respectively. The effects of season of placement and month of placement on the above performance variables were also evaluated. The analyses revealed that the performance variables NIPB, EPEF, and FCR 1500 were superior for tunnel -ventilated housing (P=0.02, 0.0001 respectively); were less variable from month to month for tunnel- ventilated housing; and except for NIPB, were better when birds were placed during the dry season (P=0.08, 0.0005 and 0.007 respectively). Financial anlaysis also showed that tunnel -ventilated house was more profitable venture than the conventional house. The net profit margin (15.38vs 3.59%) net profit per kg, (0.51 vs 0.12 BDS$, (BDS$1.00~ US $0.50)), and net profit per m squared (94.83vs13.13BDS$) were also higher for the tunnel-ventilated house.