[Asbestosis and sarcoid-like thoracic lesions: a case report]. / Asbestose et lésions thoraciques sarcoid like

Mediastinal nodes evidenced in a patient referred for an expert opinion concerning an occupational disease were found to have a sarcoid-like character. The patient was a former smoker who had been exposed to asbestos for 27 years. The patient also had an ENT neoplasia. The nodal enlargements evidenced at mediastinoscopy were the only manifestations compatible with sarcoidosis, a rare association recognized in asbestosis.

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.

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.

[Is laparoscopic surgical practice "factual" (evidence based)? Results of a prospective regional survey]. / La pratique de la chirurgie coelioscopique est-elle "factuelle" (evidence-based)? Résultats d'une enquête prospective régionale.

OBJECTIVE: Evidence-based medicine is a growing paradigm in health care. We conducted a prospective study to determine whether laparoscopic surgery is truly evidence-based in everyday practice. METHODS: A prospective regional survey was performed in 11 French hospitals (one university and 10 district hospitals) to ascertain how general laparoscopic surgery was conducted during the last 3 months of 1997. We also searched the electronic databases for original articles on laparoscopic procedures. The methodology of randomized trials was analyzed and procedures were classed by level of evidence. We assumed that an evidence-based procedure was which had been validated by well-designed randomized controlled or prospective trials giving homogeneous results. RESULTS: One half of the procedures performed had been evaluated by randomized controlled trials. Among the 428 laparoscopic procedures, 334 (78%) were found to be evidence-based (CI 74.1-81.9%). Twelve of the 18 indications for laparoscopy (67%) were evidence based (CI: 62.5%-71.5). There was no difference between university teaching hospitals and general district hospitals. CONCLUSION: Contrary to initial criticisms, the practice of laparoscopic surgery appears to be truly evidence-based in the majority of cases.

Gene therapy for oxidant injury-related diseases: adenovirus-mediated transfer of superoxide dismutase and catalase cDNAs protects against hyperoxia but not against ischemia-reperfusion lung injury.

Hyperoxia and ischemia-reperfusion cause profound lung cellular damage mediated, in part, by generation of oxygen radicals. We hypothesized that gene therapy can be used to overcome oxidant injury by augmenting intracellular antioxidant enzymes. Adult rats were injected intratracheally with an adenovirus (Ad) vector encoding human superoxide dismutase (CuZn-SOD) or catalase cDNA, a mixture of both Ad vectors, or a control Ad vector containing no exogenous gene. Expression of human catalase and CuZn-SOD was demonstrated 3 days later in distal lung epithelial cells and alveolar macrophages, using ELISA and immunochemistry. After exposure to 100% O2 for 62 hr, survival was greater in rats injected with the catalase and/or SOD Ad vectors than in control rats. Ischemia-reperfusion injury was evaluated in the isolated perfused lung model. Overexpression of SOD worsened ischemia-reperfusion injury. Interestingly, concomitant overexpression of catalase prevented this adverse effect, but did not protect against ischemia-reperfusion injury. We conclude that Ad-mediated transfer to lungs of both catalase and SOD cDNAs protects from pulmonary O2 toxicity. Absence of protection against ischemia-reperfusion using intratracheal Ad injections may be related to the lack of endothelial protection, despite epithelial expression of catalase and SOD.

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.

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 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.

Pressor responses of rat isolated tail arteries to contractile stimulation after methylene blue treatment: effect of adventitial versus intimal entry.

To test the hypothesis that drug entry site (intimal vs. adventitial surface) may be an important determinant of methylene blue (MB) action on vascular reactivity to contractile stimulation, we used preparations of rat isolated tail arteries perfused at constant flow (2 ml/min). Perfusion pressure changes reflecting vascular responses to cumulative addition of phenylephrine (PE) or dopamine (DOP) were recorded before and after MB addition (2.5 x 10(-4) M final concentration) at the intimal or adventitial surface. Intraluminal addition of MB resulted in strong potentiation of subsequent responses to intimal contractile stimulation using PE or DOP. This effect was not observed when MB was added at the adventitial surface. These results suggest that drug entry site is an important determinant of MB action on vascular responsiveness in the rat tail artery and might account for the divergent results in the literature on the vascular action of MB.

[Pneumoblastoma. Apropos of a case]. / Le pneumoblastome. A propos d'une observation.

The authors report a case of pulmonary blastoma, a rare type of pulmonary malignant tumour. The patient was treated by pneumonectomy combined with chemotherapy and radiotherapy. The outcome was favourable, and during an 11-year follow-up there was no sign of recurrence.

Methylene blue potentiates vascular reactivity in isolated rat lungs.

A bolus injection of methylene blue (1 mg), a guanylate cyclase inhibitor, or aspirin (3 mg) in the isolated rat lung preparation had little or no effect on resting perfusion pressure under normoxic condition. In contrast, methylene blue markedly potentiated hypoxic vasopressor response (4-fold) when injected before or during the alveolar hypoxic stimulation. Hemoglobin also potentiated the hypoxic pressor response. Similarly, methylene blue or aspirin augmented the pressor responses to angiotensin II (0.1-1 microgram). The increased hypoxic response induced by methylene blue was immediate and sustained. Methylene blue, when added during hypoxia in the presence of aspirin, further augmented the response to hypoxia compared with the enhanced hypoxic response observed with aspirin alone. Our results suggest that, in addition to the role of cyclooxygenase products, the pulmonary vascular bed may be regulated by endothelium-dependent factors that can be antagonized directly or indirectly by methylene blue.

[Current therapeutic attitudes on pneumothorax in adults]. / Attitudes thérapeutiques actuelles devant un pneumothorax de l'adulte.

Recent advances in thoracoscopy and surgical procedures have led to modifications in therapeutic approaches to easily diagnosed pneumothorax. These procedures make it possible to adjust therapy to the severity and underlying causes of the disease which may vary from simple bullous dystrophy to neoplasia. For simple pneumothorax, a suitable treatment may be to put the patient under observation or exsufflation, but thoracoscopy has the advantage of visualizing the lesion and, in certain cases, enables it to be treated. Surgery is indicated when an extensive bullous system is seen at thoracoscopy or when this technique is unsuccessful. A considerable reduction in the risk of relapse of this usually benign condition should be expected.

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.

[Locoregional anesthesia of the foot for forefoot surgery]. / Anesthésie locorégionale du pied pour chirurgie de l'avant-pied.

A technique of regional anaesthesia of the foot for forefoot surgery (ingrowing toe-nail, hallux valgus, amputation, etc.) is described. It consists of a block of the superficial peroneal nerve at the ankle combined with a block of the posterior tibial nerve behind the medial malleolus. A volume of 5-6 ml of 1% lidocaine or 1% mepivacaine is injected. A pneumatic tourniquet was placed on the upper part of the thigh after the patient had been given an intramuscular premedication. The results of 52 such blocks carried out in 40 patients are discussed.