Fibrinogen Saint-Germain I: a case of the heterozygous Aalpha GLY 12 --> VAL fibrinogen variant.

A fibrinogen variant was suspected based on the results of routine coagulation tests in a 2-year-old asymptomatic child. Coagulation studies showed marked prolongation of both the thrombin and reptilase times, and discrepancy was noted between the level of plasma fibrinogen as measured by a kinetic versus immunological determination. Family studies revealed that the father beared the same abnormality. Studies of purified fibrinogen revealed an impaired release of both fibrinopeptides by thrombin. Fibrin monomer polymerization and fibrin stabilization were normal. DNA sequencing revealed a heterozygous G --> T point mutation in exon 2 of the gene coding for the Aalpha chain, which substituted a Gly for Val at position 12. Although the mutation is the same as in fibrinogen Rouen, fibrinogen Saint-Germain I shows a different fibrinopeptide release pattern and a mild factor V deficiency.

Endothelial nitric oxide synthase function in pig lung after chronic pulmonary artery obstruction.

Because long-term pulmonary artery (PA) obstruction is associated with expansion of the systemic blood supply to the lung, chronic ischemia may not occur, and endothelium nitric oxide synthase (eNOS) function may be preserved in postobstructive pulmonary arteries. To test this hypothesis, we studied piglets 2 d or 5 wk after left PA ligation or a sham operation. We measured left lung ATP and lactate lung concentrations; calcium-dependent and calcium-independent NOS activities and eNOS protein; and left PA relaxations in response to acetylcholine, calcium ionophore, and sodium nitroprusside. Decreases in ATP and increases in lactate concentrations were significantly attenuated after 5 wk PA occlusion (p < 0.05 versus sham and 2-d ligation). Compared with sham and 2-d PA occlusion, calcium-dependent NOS activity and eNOS protein were lower in the long-term PA occlusion group. Calcium-independent NOS activity was unchanged. Acetylcholine and calcium ionophore relaxations were impaired after 5 wk, whereas only acetylcholine relaxation was impaired after 2-d PA occlusion. Relaxation to sodium nitroprusside remained unchanged. In conclusion, despite relative conservation of lung energy metabolism, prolonged PA occlusion decreased eNOS function and protein in postobstructive pulmonary arteries.

Protective effects of Celsior in lung transplantation.

BACKGROUND: Celsior is a new preservation solution for heart transplants that recently has been shown also to improve protection of pulmonary grafts. As these data were obtained in isolated lung preparations, we sought to perform further tests with an in vivo model of allogeneic lung transplantation. METHODS: The left lungs of 41 rats were either transplanted immediately after harvest (controls) or flushed with and cold stored in Celsior or the blood-based Wallwork solution for 5 or 12 hours. Lungs were then reperfused for 30 minutes, after which ligation of the contralateral pulmonary artery and bronchus made the recipient rat exclusively dependent on the transplanted lung. Assessment of preservation was made on functional (blood gases, pulmonary hemodynamics) and structural (dry-to-weight ratio, light microscopy, myeloperoxidase [MPO] content) end points. RESULTS: The protective effects of Celsior were primarily manifest, once the contralateral lung had been functionally excluded, as a better preservation of oxygen tensions in the 5-hour storage experiments (416 +/- 52 mm Hg vs 406 +/- 59 mm Hg in controls [p = NS] and vs 239 +/- 34 mm Hg in Wallwork [p < 0.05 vs the 2 other groups]) and a smaller increase in pulmonary vascular resistance in the 12-hour storage experiments (10.2 +/- 4.1 mm Hg/mL/minute vs 3.2 +/- 1.1 mm Hg/mL/minute in controls [p = NS] and vs 23.1 +/- 4.3 mm Hg/mL/minute in Wallwork [p < 0.02 vs Celsior, p < 0.002 vs controls]). Survival was also longer in the 12-hour preserved Celsior group. Other end points were not significantly different between the two preservative solutions. CONCLUSION: These data support the efficacy of Celsior as a flush-out and storage solution for pulmonary grafts. Given its previously documented ability to adequately preserve heart transplants, Celsior might provide a unified "solution" to thoracic organ preservation.

Pulmonary thromboendarterectomy for chronic thromboembolic obstruction of the pulmonary artery in piglets.

OBJECTIVE: The 2 main causes of death after thromboendarterectomy for chronic pulmonary thromboembolism are incomplete repermeabilization responsible for persistent pulmonary hypertension and acute high-permeability pulmonary edema. We wish to establish an experimental model of chronic pulmonary thromboembolism to replicate the conditions encountered during and after pulmonary thromboendarterectomy. METHODS: Multiple-curled coils and tissue adhesive were embolized in 6 piglets to induce complete obstruction of the left pulmonary artery, documented by angiography. After 5 weeks, the main pulmonary artery was repermeabilized by thromboendarterectomy during circulatory arrest. The left lung was reperfused ex vivo with autologous blood at constant flow, and patency of the pulmonary artery was evaluated on a barium angiogram. The endarterectomy-reperfusion procedure was also done in 6 nonembolized piglets that served as the controls. The severity of lung injury induced by 60 minutes of reperfusion was assessed on the basis of measurements of the lung filtration coefficient and of lung myeloperoxidase activity. RESULTS: Marked hypertrophy of the bronchial circulation was seen in the chronic pulmonary thromboembolism group. Thromboendarterectomy removed the organized obstructing thrombus that was incorporated into the arterial wall and restored patency of the pulmonary artery. Acute lung inflammation and high-permeability edema occurred after reperfusion, as indicated by a 1.5-fold increases in both lung filtration coefficient and lung myeloperoxidase values in the chronic pulmonary thromboembolism group; these 2 variables being correlated. CONCLUSIONS: Our model replicated the perioperative conditions of pulmonary thromboendarterectomy, suggesting that it may prove useful for improving the repermeabilization technique and for investigating the mechanisms and prevention of reperfusion injury.

Vascular endothelium viability and function after total cardiopulmonary bypass in neonatal piglets.

Endothelium dysfunction with severe pulmonary hypertension may occur after total cardiopulmonary bypass (CPB) in infants as a result of a widespread inflammatory response. The aim of this study was to separate out the effects of lung ischemia-reperfusion from membrane oxygenator-induced activation of leukocytes on the function and viability of the pulmonary and systemic endothelia in neonatal piglets submitted to 90-min total CPB followed by 60-min reperfusion or in sham animals. Hemodynamics, gas exchange, endothelial-dependent relaxation in pulmonary and femoral arteries, and lung and skeletal muscle myeloperoxidase activity were assessed before, during, and after CPB, i.e., after reperfusion. Pulmonary and aortic endothelial cells and circulating leukocytes were harvested to assess reperfusion-induced changes in endothelial cells' viability and proliferation, and leukocyte-endothelial cell adhesion and cytotoxicity. Gas exchange worsened after reperfusion with pulmonary hypertension, increase in lung but not skeletal myeloperoxidase, and reduction of endothelial-dependent relaxation in pulmonary but not femoral arteries. After reperfusion, viabilities of pulmonary and aortic endothelial cells were reduced to 50%, endothelial cell growths were faster in pulmonary arteries than aorta, and leukocyte-pulmonary endothelial cell adhesion and cytotoxicity increased. These results suggest that in total CPB lung ischemia-reperfusion aggravates the inflammatory response and predisposes the lung endothelium to leukocyte-mediated injury.

Lung reperfusion injury after chronic or acute unilateral pulmonary artery occlusion.

Because the lungs receive their blood supply from both the pulmonary and bronchial systems, chronic pulmonary artery obstruction does not necessarily result in severe ischemia. Ischemia-reperfusion (IR) lung injury may therefore be attenuated after long-term pulmonary artery obstruction. To test this hypothesis, isolated left lungs of pigs were reperfused two days (acute IR group) or 5 wk (chronic IR group) after left pulmonary artery ligation and compared to those of sham-operated animals. The severity of IR-lung injury after 60 min ex vivo reperfusion of the left lung was assessed based on lung histology and measurements of filtration coefficient (Kfc), pulmonary arterial resistance (Rpa), and lung myeloperoxidase (MPO) activity. Marked bronchial circulation hypertrophy was seen in the chronic IR group. Hemorrhagic alveolar edema was found in all acute IR lungs but not in sham or chronic IR lungs. Compared with the sham-operated controls, Kfc and Rpa increased two-fold and threefold, and MPO 1.5-fold and twofold in the chronic and acute IR groups, respectively. In conclusion, IR-induced lung injury was markedly reduced when it occurred 5 wk after pulmonary artery ligation, probably because the systemic blood supply to the lung had time to develop, limiting ischemia.

Fibrinogen Poissy I: a new case of the A alpha Arg 16His fibrinogen variant.

A fibrinogen variant was identified in a patient with disseminated intravascular coagulation and in one member of her family. Coagulation studies showed marked prolongation of both the thrombin and reptilase times and discrepancy was noted between the levels of plasma fibrinogen, determined by a kinetic vs immunological determination or light scattering assay. Studies on purified fibrinogen revealed an impaired release of fibrinopeptides by thrombin. DNA sequencing revealed a heterozygous A to G point mutation in exon 2 of the A alpha chain, which substituted Arg for His at position 16. This mutation creates a Nla III cleavage site which was used to confirm the mutation.

Effects of various timings and concentrations of inhaled nitric oxide in lung ischemia-reperfusion. The Paris-Sud University Lung Transplantation Group.

Experimental studies reveal that inhaled nitric oxide (NO) can prevent, worsen, or have no effect on lung injury in the setting of ischemia-reperfusion (I-R). We tested the hypothesis that these disparate effects could be related to differences in the timing of administration and/or concentration of inhaled NO during I-R. Isolated rat lungs were subjected to 1-h periods of ischemia followed by 1-h periods of blood reperfusion. We investigated the effects of NO (30 ppm) given during ischemia, NO (30 or 80 ppm) begun immediately at reperfusion, or NO (30 ppm) given 15 min after the beginning of reperfusion, on total pulmonary vascular resistance (PVR), the coefficient of filtration (Kfc), the lung wet/dry weight ratio (W/D) of lung tissue, and lung myeloperoxidase activity (MPO). A control group did not receive NO. NO given during ischemia had no effect on Kfc or MPO, but decreased PVR. NO (30 ppm) during reperfusion (early or delayed) decreased PVR, W/D, Kfc and MPO. NO at 80 ppm decreased PVR and MPO but not W/D or Kfc. In conclusion, NO at 30 ppm, given immediately or in a delayed fashion during reperfusion, attenuates I-R-induced lung injury. NO at 30 ppm given during ischemia or at 80 ppm during reperfusion is not protective.

Endogenous nitric oxide production and atrial natriuretic peptide biological activity in infants undergoing cardiac operations.

OBJECTIVES: To examine whether preoperative heart failure and cardiac surgery influence nitric oxide production and atrial natriuretic peptide (ANP) biological activity in infants and whether nitric oxide and ANP participate in the control of postoperative pulmonary vascular tone. DESIGN: Prospective, clinical study. SETTING: Tertiary pediatric cardiac intensive care unit in a referral cardiosurgical center. PATIENTS: Nineteen infants (median age 4 months) undergoing cardiac surgery: 13 infants with ventricular or atrioventricular septal defect associated with heart failure and pulmonary hypertension (group 1); and six infants with tetralogy of Fallot, without heart failure (group 2). INTERVENTIONS: Blood samples obtained from indwelling catheters or bypass circuit outlets. MEASUREMENTS AND MAIN RESULTS: Nitrite and nitrate blood concentrations (as a marker for nitric oxide synthesis) and the molar ratio of cyclic guanosine 3',5'-monophosphate (cGMP) to ANP (as a marker for ANP biological activity) were determined before, during, and up to 24 hrs after cardiopulmonary bypass (CPB). In group 1 patients, these biological parameters were related to postoperative pulmonary arterial pressure. Preoperative nitrite and nitrate concentrations were higher in group 1 patients than in group 2 patients (p < .02), and this difference persisted during CPB. Nitrite and nitrate concentrations 24 hrs postoperatively were lower than preoperative values in group 1 patients (p < .05) and were unchanged in group 2 patients. An inverse correlation was observed postoperatively between nitrite and nitrate concentrations and systolic pulmonary arterial pressure (r2 = 0.4, p < .05). Group 1 patients had a lower preoperative cGMP/ANP ratio than group 2 patients (p < .05), despite higher ANP levels (p < .005). The cGMP/ANP ratio decreased during CPB in both groups (p < .0001), and in group 2 patients, cGMP and ANP values remained below preoperative values < or = 24 hrs postoperatively. A correlation was observed between ANP levels and systolic pulmonary arterial pressure 2 and 4 hrs postoperatively (r2 = .4, p < .05, respectively), but no correlation was observed between ANP biological activity and postoperative pulmonary arterial pressure. CONCLUSIONS: Infants with heart failure and pulmonary hypertension have increased nitric oxide synthesis and decreased ANP biological activity; both phenomena may be involved in the pathophysiology of this clinical condition. CPB has no detectable effect on nitric oxide production but does decrease ANP biological activity. In patients with preoperative heart failure and pulmonary hypertension, endogenous nitric oxide appears to play a role in the control of postoperative pulmonary vascular tone.

Inhaled nitric oxide and pentoxifylline in rat lung transplantation from non-heart-beating donors. The Paris-Sud University Lung Transplantation Group.

BACKGROUND: In non-heart-beating donor lung transplantation, postmortem warm ischemia poses a special challenge. Inhaled nitric oxide and pentoxifylline have been shown to attenuate ischemia-reperfusion injury after lung transplantation. We hypothesized that concomitant administration of inhaled nitric oxide and pentoxifylline would result in a synergistic effect on ischemia-reperfusion lung injury. METHODS: Lungs were harvested from non-heart-beating donors after 30 minutes of in situ warm ischemia, flushed, and stored for 2 hours at 4 degrees C before left lung transplantation in rats. Inhaled nitric oxide (30 ppm) was added during cadaver ventilation and reperfusion; pentoxifylline was given intravenously throughout reperfusion. The following groups were studied (n = 8 each): control, pentoxifylline, nitric oxide, and nitric oxide+pentoxifylline. Hemodynamic indices and arterial blood gases were obtained after ligation of the right pulmonary artery. Lung myeloperoxidase and wet/dry ratio were measured after death. RESULTS: All rats that did not receive nitric oxide died within 10 minutes after ligation. Inhaled nitric oxide significantly decreased pulmonary vascular resistance and improved recipient survival. Nitric oxide + pentoxifylline improved pulmonary vascular resistance, arterial oxygen tension, and survival even further and reduced lung myeloperoxidase as compared with the group that received nitric oxide only. Preservation solution flush time was significantly decreased in both groups receiving nitric oxide, suggesting that inhaled nitric oxide used during cadaver ventilation allows for a more even distribution of the preservation solution. CONCLUSIONS: We conclude that treatment with inhaled nitric oxide + pentoxifylline results in a synergistic protection from ischemia-reperfusion injury after non-heart-beating donor lung transplantation. This is likely the result of a dual action on the graft vasculature and neutrophil sequestration.

Inhaled nitric oxide attenuates reperfusion injury in non-heartbeating-donor lung transplantation. Paris-Sud University Lung Transplantation Group.

BACKGROUND: Non-heartbeating-donor (NHBD) lung transplantation could help reduce the current organ shortage. Polymorphonuclear neutrophil (PMN) activation plays a pivotal role in ischemia-reperfusion injury (I-R), and can be inhibited by nitric oxide (NO). We hypothesized that inhaled NO might be beneficial in NHBD lung transplantation. METHODS: The effect of inhaled NO on PMNs was studied by measuring in vivo PMN lung sequestration (myeloperoxidase activity) and adhesion of recipient circulating PMNs to cultured pulmonary artery endothelial cells (PAECs) in vitro. Pigs were randomly assigned to an NO or a control group (n=9 each). In the NO group, cadavers and recipients were ventilated with oxygen and 30 parts per million of NO. After 3 hr of postmortem in situ warm ischemia and 2 hr of cold ischemia, left allotransplantation was performed. The right pulmonary artery was ligated, and hemodynamic and gas exchange data were recorded hourly for 9 hr. Recipient PMN adherence to tumor necrosis factor-alpha- and calcium ionophore-stimulated PAECs was measured before and after reperfusion, and lung PMN sequestration was determined after death. RESULTS: NO-treated animals exhibited lowered pulmonary vascular resistance (P<0.01), as well as improved oxygenation (P<0.01) and survival (P<0.05). Adhesion of PMNs to PAECs was inhibited in the NO group before (P<0.001) and after reperfusion (P<0.0001). Lung PMN sequestration was reduced by NO (P<0.05). CONCLUSIONS: Inhaled NO attenuates I-R injury after NHBD lung transplantation. This is likely due to the prevention of I-R-induced pulmonary vasoconstriction and to the direct effect on peripheral blood PMN adhesion to endothelium, which results in reduced sequestration and tissue injury.

Prevention of ischemia-reperfusion lung injury by sulfated Lewis(a) pentasaccharide. The Paris-Sud University Lung Transplantation Group.

Inhibition of polymorphonuclear neutrophil (PMN) adhesion to the pulmonary endothelium attenuates ischemia-reperfusion (I/R) lung injury. We hypothesized that 3'-sulfated Lewis(a) (SuLa), a potent ligand for the selectin adhesion molecules, may have a beneficial effect on I/R lung injury, as measured by the filtration coefficient (K(fc)), and reduce pulmonary sequestration of PMN as assessed by the lung myeloperoxidase (MPO) activity. Blood-perfused rat lungs were subjected to 30 min of perfusion, 60 min of warm ischemia, and 90 min of reperfusion after treatment with either SuLa (200 microg) or saline. Effects of SuLa on PMN adhesion to cultured human umbilical vein endothelial cells (HUVEC) stimulated with tumor necrosis factor-alpha and calcium ionophore were also investigated. Compared with preischemia conditions, I/R induced a significant increase in K(fc), which was attenuated with SuLa (80 +/- 8 vs. 30 +/- 5%; P < 0.001). SuLa reduced lung MPO and PMN adhesion to stimulated HUVEC. These results indicate that SuLa reduces I/R-induced lung injury and PMN accumulation in lung. This protective effect might be related to inhibition of PMN adhesion to endothelial cells.

Alteration of the neonatal pulmonary physiology after total cardiopulmonary bypass.

OBJECTIVES: The purpose of this study was to analyze the mechanisms associated with lung injury after cardiopulmonary bypass and to propose strategies of prevention. METHODS: Thirty-two neonatal piglets underwent 90 minutes of hypothermic cardiopulmonary bypass without aortic cross-clamping. Five experimental groups were defined: group I had standard cardiopulmonary bypass (control), group II received continuous low-flow lung perfusion during cardiopulmonary bypass, group III treatment was similar to that of group I with maintenance of ventilation, group IV received pneumoplegia, and group V received nitric oxide ventilation (30 ppm) after cardiopulmonary bypass. Data drawn from hemodynamic and gas exchange values and muscular and pulmonary tissular levels of adenosine triphosphate (in micromoles per gram) and myeloperoxidase (in international units per 100 mg) were used for comparisons before and 30 and 60 minutes after cardiopulmonary bypass. Pulmonary and systemic vascular endothelial functions were assessed in vitro after cardiopulmonary bypass on isolated rings of pulmonary and iliac arteries. RESULTS: Pulmonary vascular resistance index, cardiac index, and oxygen tension were better preserved in groups II, IV, and V. All groups disclosed a significant decrease in lung adenosine triphosphate levels and an increase in myeloperoxidase activity whereas these levels stayed within pre-cardiopulmonary bypass ranges in muscular beds. Endothelium-dependent relaxation was preserved in systemic arteries but was strongly affected in pulmonary arteries after cardiopulmonary bypass. None of the methods that aimed to protect the pulmonary vascular bed demonstrated any preservation of pulmonary endothelial function. CONCLUSION: Cardiopulmonary bypass results in ischemia-reperfusion injury of the pulmonary vascular bed. Lung protection by continuous perfusion, pneumoplegia, or nitric oxide ventilation can prevent hemodynamic alterations after cardiopulmonary bypass but failed to prevent any of the biochemical disturbances.

Prevention of reperfusion injury by inhaled nitric oxide in lungs harvested from non-heart-beating donors. Paris-Sud University Lung Transplantation Group.

BACKGROUND: In lung transplantation using non-heart-beating donors (NHBD), the postmortem period of warm ischemia exacerbates lung ischemia-reperfusion injury. We hypothesized that inhaled nitric oxide (NO) would reduce ischemia-reperfusion injury, and thus ameliorate the viability of the lung graft. METHODS: A blood-perfused, isolated rat lung model was used. Lungs were flushed and harvested from non-heart-beating donors after 30 minutes of in situ warm ischemia. The lung was then stored for 2 hours at 4 degrees C. Inhaled NO at 30 ppm was given either during the period of warm ischemia, during reperfusion, or during both periods. Lung ischemia-reperfusion injury was assessed after 1 hour of reperfusion by measuring pulmonary vascular resistance, coefficient of filtration, wet-to-dry lung weight ratio, and myeloperoxidase activity. RESULTS: A severe IR injury occurred in lungs undergoing ischemia and reperfusion without NO as evidenced by high values of pulmonary vascular resistance (6.83 +/- 0.36 mm Hg. mL-1.min-1), coefficient of filtration (3.02 +/- 0.35 mL.min-1.cm H2O-1 x 100 g-1), and wet-to-dry lung weight ratio (8.07 +/- 0.45). Lower values (respectively, 3.31 +/- 0.44 mm Hg.mL-1.min-1, 1.49 +/- 0.34 mL.min-1.cm H2O-1 x 100 g-1, and 7.44 +/- 0.43) were observed when lungs were ventilated with NO during ischemia. Lung function was further improved when NO was given during reperfusion only. All measured variables, including myeloperoxidase activity were significantly improved when NO was given during both ischemia and reperfusion. Myeloperoxidase activity was significantly correlated with coefficient of filtration (r = 0.465; p < 0.05). CONCLUSIONS: These data suggest that inhaled NO significantly reduces ischemia-reperfusion injury in lungs harvested from non-heart-beating donors. This effect might be mediated by inhibition of neutrophil sequestration in the reperfused lung.

Lasting beneficial effect of short-term inhaled nitric oxide on graft function after lung transplantation. Paris-Sud University Lung Transplantation Group.

The combination of ischemia and reperfusion after lung transplantation is characterized by endothelial damage, neutrophil sequestration, and decreased release of endothelial nitric oxide. Because nitric oxide has been shown to selectively dilate the pulmonary vasculature, abrogate neutrophil adherence, and restore endothelial dysfunction, we hypothesized that inhaled nitric oxide given for 4 hours during initial reperfusion might attenuate reperfusion injury in a porcine model of left single-lung transplantation. We tested hemodynamic and gas exchange data, lung neutrophil sequestration, and pulmonary artery endothelial dysfunction after 4 and 24 hours of reperfusion in 12 pigs randomly assigned to nitric oxide and control groups. Harvested lungs were preserved in normal saline solution for 24 hours at 4 degrees C. During transplantation, inflatable cuffs were placed around each pulmonary artery to allow separate evaluation of each lung by occluding flow. Compared with the transplanted lungs in the control group, transplanted lungs in pigs treated with inhaled nitric oxide significantly improved gas exchange, pulmonary vascular resistance, shunt fraction, and oxygen delivery at 4 and 24 hours after reperfusion. Neutrophil sequestration, as measured by the neutrophil-specific enzyme myeloperoxidase and the alveolar leukocyte count per light microscopic field, was significantly lower at 24 hours after reperfusion in the transplanted lungs of the nitric oxide group. The nitric oxide-treated native right lungs exhibited significantly reduced increase in neutrophil accumulation compared with that in control native right lungs. After 24 hours of reperfusion, endothelium-dependent relaxation to acetylcholine was similarly and severely altered in both groups. We conclude that short-term inhaled nitric oxide given during the first 4 hours of reperfusion after lung transplantation significantly attenuates reperfusion injury, improving graft function as long as 24 hours after operation. This effect is probably mediated by a decrease in neutrophil sequestration. A protective effect on the contralateral lung was also observed. Inhaled nitric oxide may be a suitable agent when an acute reperfusion phenomenon is anticipated.

Prevention of ischemia-reperfusion lung injury by inhaled nitric oxide in neonatal piglets.

Lung ischemia-reperfusion results in a decrease in the release of nitric oxide (NO) by the pulmonary endothelium. NO may have lung-protective effects by decreasing neutrophil accumulation in the lung. We tested whether NO inhalation would attenuate reperfusion-induced endothelial dysfunction and increases in microvascular permeability and total pulmonary vascular resistance (RT) by preventing neutrophil lung accumulation. After baseline determinations of RT, coefficient of filtration (Kfc), and circulating neutrophil counts, isolated neonatal piglet lungs were subjected to a 1-h period of ischemia followed by a 1-h period of blood reperfusion and reventilation with or without addition of NO (10 ppm). NO prevented reperfusion-induced increases in RT and Kfc, as well as the decrease in circulating neutrophils. After reperfusion, increases in Kfc were correlated with decreases in circulating neutrophils. NO prevented reperfusion-induced decrease in endothelium-dependent relaxation in precontracted pulmonary arterial rings. This demonstrates that inhaled NO prevents microvascular injury, endothelial dysfunction, and pulmonary neutrophil accumulation in a neonatal piglet model of lung ischemia-reperfusion.

Pentoxifylline and lung ischemia-reperfusion injury: application to lung transplantation. Université Paris-Sud Lung Transplant Group.

Pentoxifylline (PTX) attenuates neutrophil-mediated lung injury in several models of acute lung inflammation. Because pulmonary neutrophil sequestration is the main determinant of ischemia-reperfusion (IR) injury in lung transplantation, we sought to determine whether or not PTX prevented IR injury in isolated perfused rat and rabbit lungs submitted to IR, and in pigs after left lung allotransplantation. In rat lungs after IR, the coefficient of lung endothelial permeability (Kfc) increased by 112 +/- 12% in controls and by 27 +/- 8% (p < 0.001) in PTX-treated lungs. After IR, lung myeloperoxidase and blood neutrophil count decrease were lower with PTX than in controls, and the changes in Kfc were correlated with the percentage decrease in blood neutrophils during reperfusion. In rabbit lungs, endothelium-dependent relaxation in isolated pulmonary arterial rings was decreased in the control group and normal in the PTX group. In pigs ventilated with pure oxygen, the PaO2 was greater in the PTX group than in the control group (423 +/- 49 vs. 265 +/- 43 mm Hg; p < 0.05), whereas the total pulmonary vascular resistance was lower (15 +/- 1 vs. 30 +/- 9 mm Hg/L/min; p < 0.02). After reperfusion, the decrease in circulating leukocyte count fell by 35 +/- 3% in the control group and remained unchanged in the PTX group, and the leukocyte count per microscopic field in the transplanted lung was lower in the PTX group than in the control group (p < 0.02). In conclusion, PTX prevented IR lung endothelium injury and improved post-IR lung function by decreasing neutrophil lung sequestration, and this agent might be useful in clinical lung transplantation.

Reduction of ischemia-reperfusion injury by pentoxifylline in the isolated rat lung. Paris-Sud University Lung Transplantation Group.

Inhibition of pulmonary neutrophil sequestration attenuates ischemia-reperfusion (IR) lung injury. Pentoxifylline (PTX) reduced pulmonary sequestration of neutrophils and neutrophil-dependent lung injury in several experimental settings but has never been tested in IR models. We hypothesized that PTX may have a beneficial effect on IR lung injury as measured by the coefficient of filtration (Kfc) and may reduce IR-associated sequestration of neutrophils as assessed by lung myeloperoxidase (MPO) activity and by blood neutrophil count decrease during reperfusion. Three groups of isolated blood perfused rat lungs were studied: a time control group (n = 6) was perfused for 3 h, and two groups (n = 10) subjected to 1 h ischemia were treated with PTX or saline before a 2 h reperfusion. The increase in Kfc induced by IR was reduced fivefold by PTX compared with saline (+27 +/- 8% versus +112 +/- 12%, respectively; p < 0.001), and was similar to time controls (+9 +/- 9%). After IR, MPO and blood neutrophil count decrease were lower with PTX than with saline. Changes in Kfc were correlated to the percentage decrease in blood neutrophils during reperfusion. We conclude that PTX reduced rat lung IR microvascular injury. This effect may be mainly caused by decrease in lung sequestration of neutrophils during reperfusion.

[Protaminase activity of plasma. III. Role of conversion enzyme (kininase II) in protaminase activity of plasma]. / Activité protaminasique du plasma. III. Rôle de l'enzyme de conversion (kininase II) dans l'activité protaminasique du plasma.

Kininase I (carboxypeptidase N) and kininase II (angiotensin converting enzyme) were isolated from human plasma by gel filtration on Sephadex G 200, then separated and partially purified by ion exchange chromatography. These two partially purified enzymic preparations allowed us to demonstrate that protamine underwent an extensive degradation only when both kininases acted simultaneously. The effects of CoCl2, an activator, and of several inhibitors, amongst which captopril, suggest that the same enzymatic system is responsible for the in vitro protaminasic activity of diluted unfractionated plasma.

Determination of "in vitro" degradation of protamine in plasma by three different methods.

Three techniques for the quantitative or semi-quantitative determination of the degradation of protamine in plasma are described. One is based on the measurement of liberated arginine, since arginine is the single most important constituent of protamine (80% in weight). The second utilizes successive estimations of protamine by addition to a secondary heparinized medium in which excess heparin is measured by thrombin time and polybrene titration. The third method employs electrophoresis on cellulose acetate, and offers direct visualization of the soluble complexes formed between protamine and albumin, and of their degradation. When applied to an incubation mixture containing diluted plasma (1 : 8) and protamine 0.8 mg/ml, the first two methods were well correlated and showed that protamine degradation proceeded linearly with time. The third method had good semiquantitative agreement with the two former. The rate of protamine degradation was different when estimated by each of the three methods, due probably to the different physico-chemical reactions involved.