Regulation of peripheral blood flow in Complex Regional Pain Syndrome: clinical implication for symptomatic relief and pain management

Background. During the chronic stage of Complex Regional Pain Syndrome (CRPS), impaired microcirculation is related to increased vasoconstriction, tissue hypoxia, and metabolic tissue acidosis in the affected limb. Several mechanisms may be responsible for the ischemia and pain in chronic cold CPRS. Discussion. The diminished blood flow may be caused by either sympathetic dysfunction, hypersensitivity to circulating catecholamines, or endothelial dysfunction. The pain may be of neuropathic, inflammatory, nociceptive, or functional nature, or of mixed origin. Summary. The origin of the pain should be the basis of the symptomatic therapy. Since the difference in temperature between both hands fluctuates over time in cold CRPS, when in doubt, the clinician should prioritize the patient's report of a persistent cold extremity over clinical tests that show no difference. Future research should focus on developing easily applied methods for clinical use to differentiate between central and peripheral blood flow regulation disorders in individual patients

Endothelium-derived endothelin-1

One year after the revelation by Dr. Furchgott in 1980 that the endothelium was obligatory for acetylcholine to relax isolated arteries, it was clearly shown that the endothelium could also promote contraction. In 1988, Dr. Yanagisawa’s group identified endothelin-1 (ET-1) as the first endothelium-derived contracting factor. The circulating levels of this short (21-amino acid) peptide were quickly determined in humans, and it was reported that, in most cardiovascular diseases, circulating levels of ET-1 were increased, and ET-1 was then tagged as “a bad guy.” The discovery of two receptor subtypes in 1990, ET(A) and ET(B), permitted optimization of the first dual ET-1 receptor antagonist in 1993 by Dr. Clozel’s team, who entered clinical development with bosentan, which was offered to patients with pulmonary arterial hypertension in 2001. The revelation of Dr. Furchgott opened a Pandora’s box with ET-1 as one of the actors. In this brief review, we will discuss the physiological and pathophysiological role of endothelium-derived ET-1 focusing on the regulation of the vascular tone, and as much as possible in humans. The coronary bed will be used as a running example in this review because it is the most susceptible to endothelial dysfunction, but references to the cerebral and renal circulation will also be made. Many of the cardiovascular complications associated with aging and cardiovascular risk factors are initially attributable, at least in part, to endothelial dysfunction, particularly dysregulation of the vascular function associated with an imbalance in the close interdependence of nitric oxide and ET-1

Stratégie d'obtention de marchés et d'entreprise dans l'industrie britannique de la construction

Abstract Investigation of the strategy and structure of large construction firms has been largely ignored by economic historians. Distinguished as it was by relatively low concentration, and the prevalence of subcontracting, the British construction industry nevertheless gave rise to some major groups : one such being Tarmac. Set up in 1901 to market, as a road-surfacing agent, blast-furnace slag mixed with coaltar, Tarmac was to remain a family firm up till 1958, after which time is embraced a vigorous strategy of outward expansion. This came to a close in 1977-78, after heavy losses, which caused a drastic overhaul of management méthodes : to such effect that, to this day, the group stands out as the best managed of the British construction industry majors.Résumé L'étude de la stratégie et de la structure des grandes firmes de construction a été négligée par les historiens économistes. Caractérisée par un taux relativement faible de concentration, par l'importance de la sous-traitance et le faible degré d'organisation en syndicats, l'industrie britannique de la construction a cependant donné naissance à de grands groupes comme Tarmac. Constituée en 1901 pour écouler, sous forme de revêtements routiers, les laitiers de hauts-fourneaux mélangés au goudron de houille, demeurée entreprise familiale jusqu'en 1958, Tarmac s'engagea ensuite dans une vigoureuse stratégie de croissance externe. Celle-ci s'acheva en 1977-78 par d'importantes pertes, qui provoquèrent une modification en profondeur des méthodes de gestion, au point qu'aujourd'hui le groupe apparaît comme le mieux géré des « majors » de l'industrie britannique de la construction.Mc Kinlay David. Stratégie d'obtention de marchés et d'entreprise dans l'industrie britannique de la construction. In: Histoire, économie et société, 1995, 14ᵉ année, n°2. Entreprises et entrepreneurs du batiment et des travaux publics (XVIIIe-XXe siècles) sous la direction de Dominique Barjot. pp. 397-416