Contribution of close-in fallout from the French atmospheric tests in inventories of 137Cs, 241Am and plutonium (238, 239, 240) in Gambier Islands (French Polynesia) - Signatures of stratospheric fallout in the Southern Hemisphere.

The inventories of 137Cs (503 ±â€¯34 Bq.m-2), 241Am (11.3 ±â€¯1.2 Bq.m-2), 241Pu (33.7 ±â€¯3.4 Bq.m-2), 238Pu (6.82 ±â€¯0.87 Bq.m-2) and 239+240Pu (113.0 ±â€¯5.9 Bq.m-2), sum of 239Pu (100 ±â€¯11 Bq.m-2) and 240Pu (14.5 ±â€¯1.7 Bq.m-2), in the Gambier archipelago (23°S) of the French Polynesia, are well higher the global fallout at this latitude, in unequal proportions for the different radionuclides. (240Pu/239Pu)AR (AR: atomic ratio) of 0.0394 ±â€¯0.0062, and (241Pu/239Pu)AR of (2.03 ±â€¯0.39)10-4, confirm that the overwhelmingly dominant source of these radionuclides comes from local fallout during the 1970s of the French atmospheric tests of Moruroa and Fangataufa located nearly 400 km from Gambier. The signatures of the local fallout were deduced from the excess of its inventory in 137Cs and from the mixing lines established from the signatures of the global fallout, some of the test sites and the isotopic ratios measured in Gambier. Signatures obtained are 2.0 ±â€¯0.4 for 137Cs/239+240Pu, 0.045 ±â€¯0.008 for 238Pu/239+240Pu, 0.031 ±â€¯0.009 for 241Am/239+240Pu, 0.092 ±â€¯0.027 for 241Pu/239+240Pu, 0.0163 ±â€¯0.0049 for (240Pu/239Pu)AR, (0.78 ±â€¯0.23)10-4 for (241Pu/239Pu)AR. The concordance of the mixing lines of the [(240Pu/239Pu)AR, (241Pu/239Pu)AR] and the linear regression of these ratios measured in the stratosphere (40°S) during the 1970s, indicates that the signatures of the close-in deposition are also those of the stratospheric injections of the French tests. The signatures of stratospheric fallout in the Southern Hemisphere were evaluated by considering that the fission energy of these injections represents 11% and that of the Northern Hemisphere represents 89% and that the isotopic ratios of stratospheric injections remained the same over the period 1970-1974. The activity ratios deducted are 21.9 ±â€¯0.1 in 137Cs/239+240Pu, 0.11 ±â€¯0.05 in 238Pu/239+240Pu, 1.03 ±â€¯0.12 in 241Pu/239+240Pu and 0.35 ±â€¯0.04 in 241Am/239+240Pu. The associated atom ratios are 0.157 ±â€¯0.011 for (240Pu/239Pu)AR and (8.33 ±â€¯0.48)10-4 for (241Pu/239Pu)AR. These signatures appear to be consistent with the results of the inventories at Hiva Oa, located more than 1,000 km north of both French test sites, and with those found in the Australian continent, in regions not impacted by UK-test debris. The proportions of close-in tropospheric fallout from the French tests are about 90% in Gambier. They represent a proportion in the inventories of 40% for the 137Cs, 60% for 241Am and in the range between 80 and 90% for Pu isotopes.

Safety of high energy internal cardioversion for atrial fibrillation.

High energy internal cardioversion has been proposed as an alternative method to cardiovert drug refractory or external cardioversion refractory atrial fibrillation. However, the safety of this technique has not been clearly evaluated. We reviewed findings in 53 patients who underwent 55 sessions of high energy internal cardioversion (2 patients underwent 2 sessions) for termination of longstanding atrial fibrillation. Shocks energy varied from 70-270 J. Three patients had 3 shocks during the same session, 5 had 2, and 47 only 1. Success rate was 89% (success was defined as immediate conversion to normal sinus rhythm). Low cardiac output occurred in two patients, and resulted in the death of one of these individuals, a patient with significant hypertrophic cardiomyopathy and heart failure. The other patient recovered completely. In 11% of the cases, shock induced transient atrioventricular block, necessitating ventricular pacing until sinus rhythm was restored. In three patients, a moderate but asymptomatic and uncomplicated pericardial effusion was diagnosed on echocardiogram. Finally, four patients had side effects related to venous puncture, which resolved spontaneously. These results suggest that high energy internal cardioversion is effective for conversion of atrial fibrillation. However, the technique may not be optimal in patients with advanced hypertrophic cardiomyopathy and in such cases the technique should be used carefully and only in the case of failure of external cardioversion; no more than two shocks should be delivered during the same procedure. Temporary ventricular pacing should be provided in all patients and an echocardiogram should be performed before patients are being discharged.

[Mortality and morbidity in the acute phase of myocardial infarction. Comparison of 3 patient cohorts admitted to hospital over 10 years]. / Mortalité et morbidité à la phase aiguë de l'infarctus du myocarde. Comparaison de trois cohortes de patients hospitalisés espacées de 10 ans.

The management of acute myocardial infarction has been transformed over the last thirty years by a number of therapeutic innovations. The authors decide to compare the outcomes of three cohorts of unselected patients admitted to hospital at 10 year intervals, to evaluate the impact of these innovations on morbidity and mortality. Six hundred and sixty one patient admitted to the Coronary Care Unit for acute myocardial infarction were included: Group I comprised 223 patients admitted consecutively during the period 1972-1973; Group II comprised 243 patients admitted between 1982-1983 and Group III comprised 195 patients admitted between 1992-1993. The average age was comparable, about 65 years, in the 3 groups, although there were gender differences. Taking into consideration earlier hospital admission, the in-hospital mortality decreased from 25% in Group I to 21.8% in Group II and to 15.4% in Group III (p < 0.05 between the first 2 groups and the third group). This decrease in mortality is even greater in anterior wall infarction and is observed in all ages. Similarly to selected patients in large scale randomised clinical trials, the ordinary "run of the mill" patient has also benefited from therapeutic innovations over the last ten years.

[Elastic recoil after transluminal coronary angioplasty; implications of clinical and angiographic data]. / Le retour élastique après angioplastie transluminale coronaire; implications respectives des données cliniques et angiographiques.

Secondary elastic recoil after transluminal coronary angioplasty is a constant and immediate phenomenon after successful coronary angioplasty. It was studied by quantitative coronary angiography in 75 consecutive patients undergoing transluminal coronary angioplasty. This procedure was performed on lesions presumed to be responsible for the clinical presentation. The population was divided into 3 groups: stable angina (25 patients), unstable angina (25 patients) and recent post-infarction ischaemic syndromes (25 patients). There were 57 men and 18 women (mean age 59 +/- 11 years) with 31 left anterior descending (LA), 29 right coronary (RC) and 15 left circumflex (Cx) dilatations. The lesions dilated were eccentric in 29 cases and calcified in 37 cases whereas only one thrombus was detected at coronary angiography. The elastic recoil appreciated 10 mn after the last balloon inflation was 0.97 +/- 0.28 mm for the whole population. There was no significant difference between the 3 groups studies (respectively 0.94 +/- 0.24 mm; 0.96 +/- 0.26 mm; 0.99 +/- 0.33 mm). This appeared to be greater than the RC (1.06 +/- 0.30 mm) with respect to the Cx (0.86 +/- 0.23: p < 0.02) or LAD (0.92 +/- 0.25 mm: p < 0.04). Overall, a balloon to vessel diameter ratio > 1 and a lesion length > 10 mm were parameters predicting greater secondary elastic recoil (p < 0.07 and p < 0.001 respectively), whereas the degree of eccentricity only played a role in the post-infarction ischaemic syndromes and calcification only in unstable angina (p < 0.01 and p < 0.001 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)