Deployment of the DosiKit System Under Operational Conditions: Experience From a French Defense National Nuclear Exercise

Estimation of the dose received by accidentally irradiated victims is based on a tripod: clinical, biological, and physical dosimetry. The DosiKit system is an operational and mobile biodosimetry device allowing the measurement of external irradiation directly on the site of a radiological accident. This tool is based on capillary blood sample and hair follicle collection. The aim is to obtain a whole-body and local-surface dose assessment. This paper is about the technical evaluation of the DosiKit; the analytical process and scientific validation are briefly described. The Toulon exercise scenario was based on a major accident involving the reactor of a nuclear attack submarine. The design of the scenario made it impossible for several players (firefighters, medical team) to leave the area for a long time, and they were potentially exposed to high dose rates. The DosiKit system was fully integrated into a deployable radiological emergency laboratory, and the response to operational needs was very satisfactory.

Missions of the French Defense Radiation Protection Service Concerning The Medical Management of Radio-contaminated Patients

The French Defense Radiation Protection Service (SPRA) is an institution of the French Armed Forces (SSA) that provides technical support in radiation protection matters for French military units. It provides services for the armed forces and when necessary for the national public health system. The aim of this note is to describe the variety of services provided by the SPRA in France and abroad, not only in a military context but also in the broader field of radiation protection.

Ultrafractionated radiation therapy (3x per day) for glioblastoma: Preliminary results of a phase II study

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Background: Ultrafractionation radiation therapy consists in irradiating cells or tumors several times daily, delivering low doses at which hyperradiosensitivity occur. We recently reported the high efficiency of ultrafractionation radiotherapy in glioma cell lines and xenografts, and are now conducting a phase II clinical trial to determine the effect of an ultrafractionation regimen for glioblastoma patients. Methods: A prospective, multicenter, phase II study has opened for accrual in September 2003. Patients over 18 years of age who are able to give informed consent and have histologically proven, newly diagnosed and unresectable, supratentorial glioblastoma (WHO grade IV) are eligible. Three doses of 0.75 Gy spaced by at least four hours are delivered daily, five days a week for six consecutive weeks for a total of 67.5 Gy. Conformal irradiation includes the tumor bulk including a margin of 2.5 cm. Tolerance and toxicity are the primary endpoints; survival and progression-free survival are secondary endpoints. Results: To date 25 patients have been enrolled in this study, 19 currently evalualbe: 11 men and 8 women, median age 58 (range 37 to 76), median Karnofsky performance status (80 range from 70 to 100). The median time between histological diagnosis and the start of treatment is 7 weeks. The ultrafractionated radiation therapy has been well tolerated; no acute grade 3 and/or 4 CNS toxicity has been observed. Minor responses at the end of irradiation were seen in 5 patients. Median survival from initial diagnosis was 13.5 months, nine patients remain alive. Conclusions: Ultrafractionated radiation therapy is safe and well tolerated. No acute CNS toxicitiy has been observed. Overall survival of over 13 months for patients without prior debulking surgery compares favorably with other reports. Updated definitive results will be presented.

No significant financial relationships to disclose.

Cholinesterase activity as potential biomarker in two bivalves

In this study, the pH, temperature and substrate specificity for cholinesterases (ChE) assay in two bivalves was optimized: the Spanish mussel Mytilus galloprovincialis and the Asiatic clam Corbicula fluminea. The optimal values found are pH 7, 25°C, 2 mM of acetylthiocholine (ASCh) as substrate for M. galloprovincialis and pH 8, 25°C, 5 mM propionylthiocholine (PrSCh) for C. fluminea. The apparent K(m) are 30 and 70 μM for the two bivalves, respectively. In comparison with some other crustaceans and fishes, the levels of ChE activity were found to be low. The in vitro and in vivo sensitivities of the ChEs activity toward two well known pesticides: carbaryl and methylparathion (or its oxon derived form) are comparable to that observed in fishes but less than that found in crustaceans. Although further studies should be done, and other contaminants tested, the studied bivalves can be considered as interesting 'sentinel' species in the monitoring of the acute water contamination by pesticides.

Noninvasive estimation of pulmonary arterial wedge pressure with Doppler transmitral flow velocity pattern in patients with known heart disease

Pulmonary arterial wedge pressure (PAWP) is an important marker of cardiac function. Regrettably, it requires catheterization, which can occasionally result in serious complications. A noninvasive method of estimating PAWP would thus be helpful. Recent studies have indicated that the Doppler transmitral flow velocity pattern was strongly dependent on preload and could provide an estimate of PAWP. This study was therefore designed to evaluate the relation between doppler transmitral flow velocity indexes and measured PAWP in 91 patients (learning group: 73 men, mean age 57 +/- 13 years) with ischemic heart disease (n = 41), dilated (n = 29) or hypertrophic cardiomyopathy (n = 4), or aortic stenosis (n = 17). Multiple regression analysis was used to derive an equation for estimation of PAWP, which was subsequently tested in a separate group of 33 patients (testing group: 28 men, mean age 58 +/- 12 years) with similar cardiac conditions. PAWP ranged from 4 to 48 mm Hg in the learning group and from 7 to 40 mm Hg in the testing group. In the learning group, PAWP correlated with the E/A ratio (r = 0.95), atrial filling fraction (r = -0.80), peak E velocity (r = 0.79), isovolumic relaxation period (r = -0.75), and deceleration time (r = -0.61). In the learning group, PAWP was best predicted as PAWP = 18.4 + [17.1.In(E/A ratio)]. This equation allowed prediction of PAWP within 3 mm Hg of the measured value in 24 of 33 patients (73%) in the testing group. In 8 additional patients, the equation also accurately predicted the changes in PAWP induced by volume loading or intravenous nitrates (r = 0.98).(ABSTRACT TRUNCATED AT 250 WORDS)

Banking of environmental samples for short-term biochemical and chemical monitoring of organic contamination in coastal marine environments: the GICBEM experience (1986-1990). Groupe Interface Chimie Biologie des Ecosystèmes, Marins

The GICBEM (Groupe Interface Chimie Biologie des Ecosystèmes Marins) program consists of an evaluation of the ecosystem health status in the Mediterranean Sea mainly based on chemical and biochemical approaches. Specific chemical contaminants (polycyclic aromatic hydrocarbons (PAH), polychlorobiphenyls (PCB), heavy metals) in waters, sediments, and related biotransformation indicators in target organisms (mussels, fish) have been selected for a complete survey of the coastal waters. In order to provide an appropriate sampling program for standardization for each sampling cruise, various aspects have been studied: (a) parameters for the choice of the sample sites; (b) ways of collection the samples (waters, sediments, marine organisms); and (c) preparation of the samples for a short term storage on board ship and for further analyses in the ground laboratory. Methods of preparation and storage of the samples are described and could be used to initiate an environmental banking program including both possible retrospective analyses of chemical pollutants and biochemical indicators. Moreover, the correlation between chemicals (PAH) and biochemical (mixed function oxygenase activities) parameters has been studied and this demonstrates the capability of the enzyme activities as reliable pollution biomarkers.

Resistance of the atherosclerotic plaque during coronary angioplasty: a multivariate analysis of clinical and angiographic variables

The atherosclerotic lesion resistance to balloon inflation was assessed prospectively in 200 patients undergoing primary single-site balloon percutaneous transluminal coronary angioplasty (PTCA) by using an identical inflation protocol. This resistance was evaluated by the stenosis resolution pressure, which is the pressure at which the lesion mark is no longer visible on the inflated balloon. The stenosis resolution pressure distribution was normal with a mean value of 4.4 +/- 2.3 atmospheres. Multivariate analysis revealed 4 factors related to the stenosis resolution pressure: stable angina pectoris (p < 10(-6)), the presence of calcifications (p = 0.016), the occurrence of vessel wall dissection after balloon angioplasty (p = 0.005), and the absence of a branch arising in the middle of the stenosis (p = 0.047). It is concluded that the mechanical resistance of the coronary lesion is related to the anginal status, the presence of calcifications, and the occurrence of vessel wall dissection after balloon angioplasty, probably on the basis of the plaque composition.

Hemodynamic and volume correlates of left ventricular diastolic relaxation and filling in patients with aortic stenosis

OBJECTIVE

The aim of the present study was to evaluate the hemodynamic and volume correlates of early diastolic filling and isovolumetric relaxation in patients with aortic stenosis.

BACKGROUND

Left ventricular diastolic relaxation and filling have been found to be heterogeneous in patients with aortic stenosis. Potential mechanisms underlying this heterogeneity include individual differences in the severity of muscle hypertrophy or systolic dysfunction, or both, in the presence and severity of mitral regurgitation and in the level of left atrial pressure.

METHODS

Right (fluid-filled) and left (high fidelity micromanometer) ventricular pressures, left ventricular volumes (contrast angiography) and transmitral inflow dynamics (Doppler echocardiography) were measured in 17 patients with isolated severe aortic stenosis (valve area less than 0.75 cm2). Measurements included left ventricular end-diastolic and end-systolic volumes, left ventricular ejection fraction, peak positive and negative first derivative of left ventricular pressure (dP/dt), the time constant of isovolumetric relaxation (tau), left ventricular end-diastolic pressure, left ventricular mass, left ventricular end-systolic stress, mean capillary wedge pressure and peak early (E) and late (A) transmitral filling velocities. Patients were subclassified according to left ventricular ejection performance at rest and mean capillary wedge pressure.

RESULTS

Patients with normal ejection performance and normal mean capillary wedge pressure had a normal rate of isovolumetric left ventricular pressure decay and an abnormal diastolic filling pattern, with diastolic filling occurring primarily during atrial systole. In contrast, in patients with systolic dysfunction and elevated mean capillary wedge pressure, isovolumetric pressure decay was prolonged and diastolic filling occurred essentially during the rapid filling period, with reduced atrial contribution to left ventricular filling and a short isovolumetric relaxation period. Stepwise multiple linear regression analysis identified two variables as independent predictors of transmitral velocity profile and three variables independently predictive of the rate of left ventricular pressure decay. The single most important predictor of transmitral filling pattern was the pulmonary capillary wedge pressure (p less than 0.0001), followed by the left ventricular peak negative dP/dt (p = 0.002). The single most powerful predictor of the rate of reduction in left ventricular pressure was left ventricular mass index (p less than 0.0001), followed by end-systolic volume index (p = 0.0002) and left ventricular peak negative dP/dt (p = 0.0029).

CONCLUSIONS

In patients with aortic stenosis, left ventricular filling is essentially determined by left atrial pressure, whereas isovolumetric relaxation more closely depends on the severity of muscle hypertrophy and chamber dilation.

Flow-induced vasomotor response to tachycardia of the human internal mammary artery and saphenous vein grafts late following bypass surgery

Increasing blood flow results in endothelium-dependent vasodilation of angiographically normal epicardial coronary arteries in humans. To compare the ability of internal mammary artery (IMA) and saphenous vein (SV) used as coronary artery bypass grafts to adapt their vasomotor tone to an increase in myocardial blood flow demand induced by tachycardia, 10 IMA and seven SV grafts were studied by quantitative angiography more than 6 months (range, 6-82 months) after surgery in 17 patients. All grafts were angiographically smooth and implanted to large nonakinetic perfusion zones. Angiograms were obtained in basal sinus rhythm (71 +/- 10 beats/min), during atrial pacing (129 +/- 9 beats/min), and after intragraft infusion of 1 mg isosorbide dinitrate (ISDN). In basal sinus rhythm, the cross-sectional area of SV was superior to that of IMA (10.7 +/- 3.6 versus 5.4 +/- 1.7 mm2; p less than 0.01). All IMA dilated during pacing (+14.8 +/- 11.5%; p less than 0.005) and a further increase in IMA cross-sectional area occurred after ISDN (+27.4 +/- 20.1% versus basal; p less than 0.005). In contrast, SV failed to dilate during pacing (+0.3 +/- 5.4%; p = NS) and after ISDN (+0.7 +/- 6.0% versus basal; p = NS). Thus, an increase in myocardial blood flow demand induced by tachycardia results in dilation of IMA but not of SV grafted on coronary vessels. The ability of the endothelium to modulate the vasomotor tone of IMA grafts in response to changes in blood flow could contribute to their excellent long-term functional results after coronary artery bypass surgery.

Asynchronous (segmental early) relaxation impairs left ventricular filling in patients with coronary artery disease and normal systolic function

Asynchronous segmental early relaxation, defined as a localized early segmental outward motion of the left ventricular endocardium during isovolumetric relaxation, has been associated with an altered left ventricular relaxation rate. To determine whether asynchronous segmental early relaxation also results in impaired left ventricular filling, early diastolic ventricular wall motion and Doppler-derived left ventricular filling indexes were examined in 25 patients with documented coronary artery disease and normal systolic function. Patients were further classified into two groups according to the presence (n = 15, group 1) or absence (n = 10, group 2) of asynchronous early relaxation at left ventriculography. A third group of 10 age-matched normal subjects served as a control group. No differences were observed between the two patient groups with coronary artery disease with respect to age, gender distribution, heart rate, left ventricular systolic and diastolic pressures or extent and severity of coronary artery disease. No differences in transmitral filling dynamics were observed between group 2 patients and age-matched control subjects. Conversely, group 1 patients had significantly lower peak early filling velocities (44 +/- 11 vs. 58 +/- 11 cm/s, p less than 0.01), larger atrial filling fraction (45 +/- 4% vs. 38 +/- 4%, p less than 0.001), lower ratio of early to late transmitral filling velocities (0.6 +/- 0.08 vs. 0.99 +/- 0.18, p less than 0.001) and a longer isovolumetric relaxation period (114 +/- 12 vs. 90 +/- 6 ms, p less than 0.001) compared with group 2 patients and control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of balloon size and stenosis morphology on immediate and delayed elastic recoil after percutaneous transluminal coronary angioplasty

After successful coronary angioplasty, the minimal luminal diameter of the dilated coronary artery segment is generally smaller than the diameter of the largest balloon catheter at the maximal inflation pressure. The determinants of this phenomenon were studied in 28 patients. Biplane angiograms were obtained after intracoronary administration of isosorbide dinitrate (1 mg) before, immediately and 24 h after coronary angioplasty. Balloon and coronary luminal diameters were measured by automated contour detection. Immediately after the procedure, the difference between inflated balloon diameter and minimal luminal diameter averaged 0.93 +/- 0.43 mm for the entire group and was greater both in eccentric stenoses (1.13 +/- 0.39 vs. 0.70 +/- 0.36 mm; p less than 0.01) and after angioplasty with an oversized balloon (1.20 +/- 0.37 vs. 0.71 +/- 0.33 mm; p less than 0.005). At 24 h, the balloon - minimal luminal diameter difference was unchanged at the group level (0.86 +/- 0.38 mm, but the minimal luminal diameter increased significantly in the subgroup of coronary segments dilated with an oversized balloon (1.97 +/- 0.37 vs. 1.81 +/- 0.28 mm; p less than 0.05). Thus, the difference between the minimal diameter of a dilated coronary segment immediately after a successful coronary balloon angioplasty procedure and the maximal diameter of the inflated balloon catheter is dependent both on eccentricity of the stenosis and on the balloon/artery diameter ratio. Moreover, the increase in minimal luminal diameter 24 h after angioplasty performed with an oversized balloon suggest that in addition to elastic recoil partly reversible factors related to vessel barotrauma are involved.

Angioplasty of coronary bifurcation stenoses: immediate and long-term results of the protecting branch technique

Percutaneous transluminal angioplasty (PTCA) of coronary stenoses involving major bifurcations carries a small but significant risk of side branch occlusion which can be avoided by simultaneously using multiple dilatation systems. Among 1,275 PTCA procedures performed between 1984 and 1988 in 1,035 consecutive patients, 42 double wire procedures were applied (4%) to protect and/or dilate major coronary side branches. A total of 80 coronary stenoses were attempted of which 76 were located on a bifurcation and 4 on other segments. In the first 11 patients (group A), 2 guiding catheters were used and PTCA of each vessel was successfully performed by means of separate double lumen over-the-wire balloon catheters. In the next 31 patients (group B), 2 guidewires were advanced through a single guiding catheter and PTCA was attempted using "Monorail" balloon catheters sequentially advanced over the wires. In group B, a successful PTCA was obtained in 29 patients (93%) but twisting of the wires hampered balloon progression in 5 cases, such that dilatation could only be performed by stepping back to a single wire technique. The procedure time in group B was significantly shorter than in group A: 144 +/- 30 versus 230 +/- 52 minutes (p = .01). Repeat angiography was performed in 35 out of 40 patients (87%) after a mean of 180 +/- 46 days following successful PTCA. Angiographic restenosis was present in 37% (24/65) of bifurcation segments which, in our experience, is not significantly different from the angiographic restenosis rate in less complex lesions (248/740; 34%; NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Responses of antioxidants and lipid peroxidation in mussels to oxidative damage exposure

1. The aim of this work was to evaluate the relationships between free radical scavengers and lipid peroxidation in the common mussel Mytilus edulis. 2. Mussels were exposed to compounds known for their ability to produce free radicals (carbon tetrachloride, CCl4) and reactive oxygen species via redox cycling (menadione) and the effects on digestive gland, gills and remaining tissues were studied. 3. Lipid peroxidation parameters and the status of free radical scavengers (glutathione, vitamins A, E and C) were affected more by exposure to menadione than to CCl4. 4. The observed changes in the free radical scavengers content are indicative of a role in detoxication of damaging reactive species.

Results of percutaneous mitral commissurotomy in 200 patients

To assess the feasibility and efficacy of percutaneous mitral commissurotomy (PMC), the procedure was attempted in 200 patients with severe mitral stenosis. There were 154 women and 46 men, their mean age was 43 +/- 16 years (range 13 to 79) and 15 were older than 70 years of age. Forty-four had had previous surgical commissurotomy. Forty were in New York Heart Association class II, 152 in class III and 8 in class IV. In regard to valvular anatomy, 67 had calcified valves, 58 had pliable valves and only mild subvalvular disease, and 75 had flexible valves but extensive subvalvular disease. Grade 1+ mitral regurgitation was present in 62 and grade 2+ in 2. In 11 patients the procedure was discontinued because of complications in 3 and technical failure in 8. Six of the 8 technical failures occurred during the first 15 attempts. Effective PMC was performed in 189 patients using 1 balloon in 23 and 2 balloons in 166. After PMC, there was a significant improvement in mean left atrial pressure (21 +/- 7 to 12 +/- 5 mm Hg, p less than 0.0001), mean mitral gradient (16 +/- 6 to 6 +/- 2 mm Hg, p less than 0.0001), cardiac index (2.6 +/- 0.8 to 3.1 +/- 0.8 liters/min/m2, p less than 0.001) and valve area assessed by hemodynamics (1.1 +/- 0.3 to 2.2 +/- 0.5 cm2, p less than 0.0001) and 2-dimensional echocardiography (1 +/- 0.3 to 1.9 +/- 0.4 cm2, p less than 0.0001). No patient died. Embolism occurred in 8 (4%), with no further sequelae. Sixteen (8%) had atrial septal defect detected by oxymetry.(ABSTRACT TRUNCATED AT 250 WORDS)