Clinical and microcirculatory effects of transcutaneous CO2 therapy in intermittent claudication. Randomized double-blind clinical trial with a parallel design

Background: This randomized, double blind trial determined the short and long-term clinical and hemodynamic vasodilator effects induced by percutaneous applications of natural CO2 gas in patients with moderate Fontaine stage II. Patients and methods: 62 patients with intermittent claudication (100-500 meters) were randomized to 18 consecutive days of CO2 treatment or placebo (air). The gas fluids were applied at a constant temperature of 30°C on pre-humidified skin. The effects of the treatment were evaluated by total distance walked (primary criterion) and hemodynamic and microcirculatory findings. Patients also answered a quality of life questionnaire. Results: The Strandness test showed a significant increase in total distance walked (+ 131 meters, 66%; p = 0.001) and pain-free distance (+ 81 meters, 73%; p = 0.02) after 18 days of CO2 treatment. The improvement was maintained 3 and 12 months later. The systolic pressure index (ABI) increased by 37% (p = 0.001) 1 minute after treadmill walking and ABI recovery time decreased significantly by 38% (p = 0.002). Microcirculatory findings showed an increase in systolic pressure of the great toe (13%; p &lt; 0.0001), in baseline pO2 (20%; p = 0.01) and in vasomotion (78%; p = 0.001) in the treatment group. The improvement in total walking distance was correlated with the increase in ABI and peripheral cutaneous oxygenation. Patients’ subjective assessments corroborated the benefits. No significant change was observed in the placebo group. Conclusions: This study demonstrates that 18 consecutive days of percutaneous CO2 treatment significantly increases walking distance in patients with moderate intermittent claudication. This effect, which was associated with an increase in peripheral systolic pressure and pO2, is evidence of a better ability to withstand effort. </jats:p

14. Commission des Étalons de Longueur d’onde et des Tables de Spectres Solaires

The 1932 report of this Commission, and the report of the ensuing discussion, revealed an unsatisfactory position with regard to sources of the red line of cadmium which could be relied upon to give the adopted standard value for the wave-length 6438.4696 x 10−10 metre.Dr Meggers has summarised the position very clearly in a recent paper on “ Interference Measurements in the Spectra of Noble Gases” (B.S.J. Research, 13, 293, 1934) and has expressed a strong preference for the specification of the Michelson lamp adopted in 1927 by the International Conference of Weights and Measures (see Trans I.A.U. 4, 58, 1932). He points out that the I.A.U. specification of 1925 is less restricted, inasmuch as it does not exclude high-frequency excitation and makes no mention of the volume or capillary bore of the tube, but requires that it must give interferences with differences of path of at least 200,000 waves. The last condition is considered objectionable on the ground that this is less than half of the theoretical or actual limit of the Michelson tube, and it is further considered that cadmium sources in which any such reduction in interference order occurs will certainly yield a different value for the primary standard.</jats:p

14. Commission des Étalons de Longueur D’Onde et des Tables de Spectres Solaires

The red radiation, 6438.4696 A., emitted by a cadmium lamp of Michelson type was first chosen in 1907 by the International Union for Co-operation in Solar Research (Trans. I.U.S.R. 2, 109, 1907) as a definition of the unit of wave-length. This primary standard was subsequently adopted by the International Astronomical Union (Trans. I.A.U. 1, 35, 1922) and by the International Committee on Weights and Measures (Procès-Verbaux Comité Int. Poids et Mesures (2), 12,67,1927). Specifications for the production of this primary standard were adopted provisionally by the I.A.U. in 1925 (Trans. I.A.U. 2, 47, 232, 1925), and by the I.C.W.M. in 1927 (Procès-Verbaux Comité Int. Poids et Mesures (2), 12, 67, 1927). Three reports of this Commission (Trans. I.A.U. 3, 77, 236, 1928; ibid. 4, 58, 233,1932; ibid. 5, 81, 299, 1935) have discussed the divergences in these specifications and pointed out the unsatisfactory features of each. This discussion culminated in a revised specification (Trans. I.A.U. 5, 303, 1935) which was adopted unanimously by the I.C.W.M. in 1935 (Procès-Verbaux Comité Int. (2), 17, 91,1935).</jats:p

14. Commission des Étalons de Longueur d’Onde et des Tables de Spectres Solaires

In the 1928 report of this Commission, reference was made to differences in the specifications for the production of the red cadmium line adopted by the International Conference of Weights and Measures in 1927 and by the International Astronomical Union in 1925. The difference appears to have arisen mainly from the inadvertent adherence of the International Conference to the text of the provisional recommendation of the Commission on Wave-lengths (Tr. I.A.U. 2, 47) instead of to that finally adopted (p. 232).</jats:p

9. Commission des Instruments Astronomiques

Matériaux. La fabrication de grands disques de quartz a été poursuivie aux États-Unis; mais aucun résultat n’a encore été communiqué à la Commission.Mlle Clavier, de l’Observatoire de Paris, a étudié des miroirs en acier inoxydable, taillés, polis optiquement et argentés. Deux points d’ordre chimique restaient à élucider pour rendre pratique l’emploi de cette matière: (a) l’argenture, qui ne donnait jamais de couches bien régulières et adhérentes; (b) l’enlèvement de l’argent terni, en vue d’une argenture nouvelle.</jats:p