To investigate the physiological role of atrial natriuretic factor (ANF) in patients with hypoxic pulmonary hypertension secondary to chronic obstructive lung disease (COLD), we infused synthetic alpha-human ANF in seven such patients, and investigated the physiological correlates to circulating peptide levels in 24 patients with COLD. ANF infusion, at incremental rates of 0.01, 0.03, and 0.1 micrograms/kg.min, increased basal plasma immunoreactive (ir) ANF (136 +/- 38 pg/ml) by 3-, 10-, and 26-fold, respectively, and reduced pulmonary artery pressure (from 33 +/- 3 to 25 +/- 2 mmHg, P less than 0.001) and systemic arterial pressure (from 88 +/- 4 to 79 +/- 4 mmHg, P less than 0.001) in a dose-related fashion. Cardiac index increased by 13.5% (P less than 0.01) while heart rate was unchanged. Cardiac filling pressures decreased at 0.1 micrograms/kg.min ANF. Pulmonary and systemic vascular resistance fell by 37% (P less than 0.001) and 19% (P less than 0.001), respectively. Arterial oxygenation was impaired during ANF infusion, suggesting partial reversal of hypoxic pulmonary vasoconstriction. Plasma renin activity remained unchanged but aldosterone fell by 44% (P less than 0.01). The levels of plasma irANF in 24 patients correlated directly with the degree of hemoconcentration (r = 0.67, P less than 0.001), respiratory acidosis (r = -0.65, P less than 0.001), and pulmonary hypertension (r = 0.52, P less than 0.01). The results suggest that ANF may serve as a potent pulmonary vasodilator involved in the circulatory homeostasis of patients with COLD.
In patients with long unilateral iliofemoral occlusive disease unfit for percutaneous transluminal angioplasty (PTA), most surgeons would choose some type of prosthetic bypass (aortounifemoral, iliofemoral or cross over). All these bypasses would provide excellent early results, but some may not be sufficient in patients with a good life expectancy who also need durable patency. The purpose of the study was to compare the long-term results of four types of arterial reconstructions. Over 20 years, 468 unilateral iliofemoral occlusions were treated primarily by one of the following techniques: aortounifemoral bypass (group 1, n = 108), iliofemoral bypass (group 2, n = 144), crossover bypass (group 3, n = 108), and iliofemoral endarterectomy (group 4, n = 108). Patients in group 3 presented with more severe comorbidities, and patients in group 4 had more superficial femoral artery occlusions. All data were prospectively registered after discharge and during the survey. Patency was assessed with duplex ultrasonography on a yearly basis. Perioperative complications and death rates were similar in all groups. The standard error was less than 10% for a period of over 10 years in all groups, except for group 3, in which it was more than 10% after 8 years. At 8 years, primary patency rates in groups 1, 2, 3, and 4 were 79%, 66%, 74%, and 89%, respectively. The difference was significant between group 4 and group 2 ( p < .02) and group 3 ( p < .01). Secondary patency and limb salvage rates were not significantly different. In this study, for an equal perioperative risk, the primary patency rates of iliac endarterectomies were superior to those of the other techniques, suggesting that these procedures should be the first choice in patients in good physical condition. Iliofemoral bypasses and crossover bypasses needed much more redo surgery. A crossover bypass should be reserved for patients who are unfit for an abdominal approach or who have a short life expectancy.
Un 1er vaccin plasmatique a ete cree en 1981, remplace des 1986 par des vaccins recombinants issus du genie genetique. En 1991, l’Organisation Mondiale de la Sante (OMS) a recommande la vaccination universelle des enfants. Dans les pays a forte endemie VHB qui ont mis precocement en place un programme de vaccination a la naissance associee au rattrapage chez l’adolescent, une importante diminution de l’incidence des hepatites et du carcinome hepatocellulaire a deja ete observee chez les enfants, faisant du vaccin contre le VHB le premier vaccin anticancereux. Le vaccin, tres immunogene permet la protection de 95 % des sujets ayant recu un schema vaccinal optimal. En raison d’une immunite cellulaire et d’une reponse anamnestique rapide en cas de contact avec l’Ag HBs, il n’est pas necessaire d’effectuer des rappels a distance de la vaccination initiale. En France, pays de faible endemie, la politique vaccinale repose sur la vaccination des nourrissons, ainsi que l’identification et la vaccination de groupes a risque eleve d’exposition au VHB. Le taux de couverture vaccinale, longtemps faible, augmente depuis 2008, date du remboursement du vaccin hexavalent, pour atteindre 92 % de couverture une dose chez les enfants nes en 2014. Cette observation laisse esperer une immunisation correcte des jeunes adultes dans 20 ans ; en revanche, le taux de couverture des enfants et adolescents reste faible (environ 40 %). Le taux de vaccination de certains groupes a risque reste egalement insuffisant : 22 a 45 % chez les usagers de drogue, environ 60 % chez les homosexuels masculins, environ 10 % dans les populations frequentant les centres de depistages anonymes et gratuits. Apres 20 ans de polemique en France sur le risque de sclerose en plaques apres vaccination anti-VHB, le debat est clos : il n’y a pas de lien entre vaccin et affections neurologiques demyelinisantes. En conclusion, la France semble sortir de son retard de vaccination chez le nourrisson. Les efforts doivent maintenant porter sur le retour de la confiance dans la vaccination pour ameliorer le rattrapage des adolescents et la vaccination des sujets non immunises a risque.
