Response functions of imaging plates to photons, electrons and 4He particles.

Imaging plates from Fuji (BAS-SR, MS, and TR types) are phosphor films routinely used in ultra high intensity laser experiments. However, few data are available on the absolute IP response functions to ionizing particles. We have previously measured and modeled the IP response functions to protons. We focus here on the determination of the responses to photons, electrons, and (4)He particles. The response functions are obtained on an energy range going from a few tens of keV to a few tens of MeV and are compared to available data. The IP sensitivities to the different ionizing particles demonstrate a quenching effect depending on the particle stopping power.

Response functions of Fuji imaging plates to monoenergetic protons in the energy range 0.6-3.2 MeV.

We have measured the responses of Fuji MS, SR, and TR imaging plates (IPs) to protons with energies ranging from 0.6 to 3.2 MeV. Monoenergetic protons were produced with the 3.5 MV AIFIRA (Applications Interdisciplinaires de Faisceaux d'Ions en Région Aquitaine) accelerator at the Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG). The IPs were irradiated with protons backscattered off a tantalum target. We present the photo-stimulated luminescence response of the IPs together with the fading measurements for these IPs. A method is applied to allow correction of fading effects for variable proton irradiation duration. Using the IP fading corrections, a model of the IP response function to protons was developed. The model enables extrapolation of the IP response to protons up to proton energies of 10 MeV. Our work is finally compared to previous works conducted on Fuji TR IP response to protons.

[Prevalence of eating disorders in early adolescent students]. / Prevalencia de trastornos alimentariosen estudiantes adolescentes tempranos.

OBJECTIVE: To measure the prevalence of Eating Behavior Disorders (EBD) in Spanish early-adolescent students using standardized methods. METHODS: A two-stage survey of prevalence of ED in a representative sample of 12 to 13 year old students in 2007 in Zaragoza (Spain). Standard evaluation: We used a two-phase cross sectional design, which involved the screening with questionnaires (EAT at a cutoff score of 20) and subsequent semi-structured interviews (SCAN) of screen-positive and screen-negative subjects. We calculated the sociodemographic characteristics, ED prevalence with their 95% confidence intervals (CI) with Confidence Interval Analysis (C.I.A.) disk version 2.0.0 (Altman et al, 2000). The study is financed by F.I.S. PI 05/2533 (Spain Health Department). RESULTS: In 2007 we studied 701 students seventh-grade, ages 12 to 13, girls and boys, in 9 public and private schools in Zaragoza (30 classrooms). In the second phase 164 preteens agreed to proceed with the clinical evaluation (63 at risk, high scorers; 101 selected sample not at risk). ED prevalence was 0.7% EDNOS F 50.9 (CI 95%: 0.3%-1.7%). CONCLUSION: The ICD-10 point prevalence rates of ED population in Spanish preteen students is similar to those reported for other developed countries. The prevalence of subclinical ED is substantially higher than that of full-syndrome.

Prevalencia de trastornos alimentarios en estudiantes adolescentes tempranos / Prevalence of eating disorders in preteen students

Introducción. Objetivos: medir la prevalencia de lostrastornos de la conducta alimentaria (TCA) en adolescentestempranos zaragozanos con métodos estandarizados.Métodología. Estudio de corte en dos estadios de prevalenciaen una muestra representativa de estudiantes españolesde 12 a 13 años en 2007 en colegios de Zaragoza.Evaluación estándar: diseño de corte en dos estadios concribado con cuestionarios autocumplimentados (EAT-26 conpunto de corte de 20) y entrevista individual semiestructurada(SCAN) de sujetos con criba positiva y negativa. Se calculanlas características sociodemográfi cas, prevalencia de TCAcon sus intervalos de confi anza 95% (CI) con Confi dence IntervalAnalysis (C.I.A.) disk version 2.0.0 (Altman et al, 2000).El estudio se fi nancia con fondos F.I.S. PI 05/2533.Resultados. En 2007 se estudia 701 alumnos de 1º deEnseñanza Secundaria Obligatoria, de 12 y 13 años, chicos ychicas, en 9 centros de secundaria públicos y privados concertados(30 aulas) en Zaragoza (Spain). En la segunda fase164 adolescentes aceptan proceder a la evaluación clínica(163 con riesgo, altas puntuaciones en EAT-26; 101 seleccionadosde la muestra sin riesgo). La prevalencia puntualde TCA es el 0,7% de Trastornos Conducta Alimentaria noespecifi cados (TCANE) F 50.9 (CI 95%: 0,3%-1,7%).Conclusiones. Las tasas de prevalencia puntual de TCACIE-10 en la población zaragozana de estudiantes adolescentestempranos es similar a la publicada en otros paísesdesarrollados. La prevalencia de TCA subclínicos o atípicosque no cumplen todos los criterios diagnósticos es sustancialmentemayor que los síndromes completos(AU)

Introduction. Objective: To measure prevalence of Eating Disorders (ED) in Spanish Preteen students using standardized methods. Methods. A two-stage survey of prevalence of ED in a representative sample of 12 to 13 year old students in2007 in Zaragoza (Spain). Standard evaluation: We used a two-phase cross sectional design, which involved the screening with questionnaires (EAT at a cutoff score of20) and subsequent semi-structured interviews (SCAN) of screen-positive and screen-negative subjects. We calculated the sociodemographic characteristics, ED prevalence with their 95% confidence intervals (CI) with Confidence Interval Analysis (C.I.A.) disk version 2.0.0 (Altman et al, 2000). The study is financed by F.I.S. PI 05/2533 (Spain Health Department).Results. In 2007 we studied 701 students seventh-grade, ages 12 to 13, girls and boys, in 9 public and private schools in Zaragoza (30 classrooms). In the second phase 164 preteen agreed to proceed with the clinical evaluation (63 at risk, high scorers; 101 selected sample not at risk). ED prevalence was 0.7% EDNOS F 50.9 (CI 95%: 0.3%-1.7%). Conclusion. The ICD-10 point prevalence rates of ED population in Spanish Preteen students is similar to those reported for other developed countries. The prevalence of subclinical ED is substantially higher than that of full-syndrome (AU)

Preparation of explosive nanoparticles in a porous chromium(III) oxide matrix: a first attempt to control the reactivity of explosives.

This paper reports the first attempt to control the combustion and the detonation properties of a high explosive through its structure. A porous chromium(III) oxide matrix produced by the combustion of ammonium dichromate was infiltrated by hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The structure of the Cr(2)O(3) matrix was studied by both scanning and transmission electron microscopy (SEM, TEM); the Cr(2)O(3)/RDX nanocomposites were characterized by nitrogen adsorption. A mathematical model based on these techniques was used to demonstrate that the Cr(2)O(3) matrix encloses and stabilizes RDX particles at the nanoscale. The decomposition process of the nanocomposites was investigated by atomic force microscopy (AFM). The reactivity and sensitivity of the nanocomposites were studied by impact and friction tests, differential scanning calorimetry (DSC), time-resolved cinematography and detonation experiments, and were correlated with their structure. The size of RDX nanoparticles and their distribution in the Cr(2)O(3) matrix have an important influence on their reactivity. The reactive properties of nanostructured RDX differ significantly from those of classical micron-sized RDX. For instance, the melting point disappears and the decomposition temperature is significantly lowered. The quantization of the explosive particles in the Cr(2)O(3) matrix decreases the sensitivity to mechanical stress and allows controlling the decomposition mode-i.e. combustion versus detonation.

Activation of nucleus tractus solitarius 5-HT2A but not other 5-HT2 receptor subtypes inhibits the sympathetic activity in rats.

Our first aim was to elucidate the mechanisms underlying the hypotensive response elicited by 5-HT(2) receptor activation in the nucleus tractus solitarius (NTS). In pentobarbitone-anaesthetized rats, intra-NTS administration of 2,5-dimethoxy-4-iodoamphetamine (DOI), a wide spectrum 5-HT(2) receptor agonist, but not an antagonist of selective 5-HT(2B) and 5-HT(2C) receptors, produced a decrease in blood pressure and heart rate. The maximal cardiovascular changes obtained by DOI (0.5 pmol) could be almost completely abolished by prior intra-NTS microinjection (10 pmol) of MDL-100907, a selective 5-HT(2A) receptor antagonist, but not by 5-HT(2B) or 5-HT(2C) receptor antagonists. In addition, using extracellular recordings we found that the large majority of identified cardiovascular rostroventrolateral medulla (RVLM) neurons were almost totally inhibited by NTS 5-HT(2A) receptor stimulation. We then investigated whether intra-NTS administration of a subthreshold dose (0.05 pmol) of DOI, known to facilitate the cardiovagal component of the baroreflex, could also modulate the sympathoinhibitory component of this reflex. These experiments showed that neither the decrease in the activity of the cardiovascular RVLM neurons and lumbar sympathetic nerve activities produced by aortic occlusion (gain of the baroreflex), nor the hypotensive response elicited by aortic nerve stimulation, were potentiated by the microinjection of DOI under such conditions. These data show that activation of 5-HT(2A), but not 5-HT(2B) or 5-HT(2C), receptors, located on NTS neurons, elicits depressor and bradycardic responses, and that this 5-HT(2A)-mediated hypotension is produced via the inhibition of RVLM cardiovascular neurons. In addition, NTS 5-HT(2A) receptor activation facilitates the cardiac but not the sympathetic baroreflex response.

Cardiac baroreflex facilitation evoked by hypothalamus and prefrontal cortex stimulation: role of the nucleus tractus solitarius 5-HT2A receptors.

We previously showed that serotonin (5-HT2) receptor activation in the nucleus of the tractus solitarius (NTS) produced hypotension, bradycardia, and facilitation of the baroreflex bradycardia. Activation of the preoptic area (POA) of the hypothalamus, which is involved in shock-evoked passive behaviors, induces similar modifications. In addition, previous studies showed that blockade of the infralimbic (IL) part of the medial prefrontal cortex, which sends projections to POA, produced an inhibitory influence on the baroreflex cardiac response. Thus, to assess the possible implication of NTS 5-HT2 receptors in passive cardiovascular responses, we analyzed in anesthetized rats the effects of NTS inhibition and NTS 5-HT2 receptor blockade on the cardiovascular modifications induced by chemical (0.3 M D,L-homocysteic acid) and electrical (50 Hz, 150-200 microA) stimulation of IL or POA. Intra-NTS microinjections of muscimol, a GABAA receptor agonist, prevented the decreases in blood pressure and heart rate normally evoked by IL or POA activation. In addition, we found that intra-NTS microinjection of R(+)-alpha-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenylethyl)]-4-piperidine-methanol, a specific 5-HT2A receptor antagonist, did not affect the decreases in cardiovascular baseline parameters induced by IL or POA stimulation but prevented the facilitation of the aortic baroreflex bradycardia normally observed during IL (+65 and +60%) or POA (+70 and +69%) electrical and chemical stimulation, respectively. These results show that NTS 5-HT2A receptors play a key role in the enhancement of the cardiac response of the baroreflex but not in the changes in basal heart rate and blood pressure induced by IL or POA stimulation.

Functional interaction between nucleus tractus solitarius NK1 and 5-HT3 receptors in the inhibition of baroreflex in rats.

OBJECTIVE: Previous data showed that in the nucleus tractus solitarius (NTS), 5-HT(3) receptors are critically involved in the inhibition of cardiac baroreceptor reflex response occurring during the defense reaction. Since stimulation of NTS NK(1) receptors has been found to inhibit the baroreflex bradycardia, we examined in this study whether this reflex response is inhibited during the defense reaction via an interaction between NK(1) and 5-HT(3) receptors. METHODS: For this purpose, we analyzed in urethane-anaesthetized rats the effects of intra-NTS GR205171, a selective NK(1) receptor antagonist, on the baroreflex bradycardia inhibition observed either during the defense reaction triggered by electrical stimulation of the dorsal periaqueductal grey matter (dPAG) or after NTS 5-HT(3) receptor activation. RESULTS: Intra-NTS GR205171, reversed, in dose-dependent manner, the inhibitory effect of dPAG stimulation on baroreflex bradycardia. This reversion was of 49% when both sinus carotid and aortic baroreceptors were stimulated by phenylephrine, and of 84% when aortic depressor nerve was stimulated. Similarly, intra-NTS GR205171 reversed partially or almost totally the inhibitory effect of local microinjections of phenylbiguanide, a 5-HT(3) receptor agonist, on baroreflex bradycardia induced either by phenylephrine administration or aortic nerve stimulation, respectively. CONCLUSION: These results strongly suggest that NK(1) receptors contribute downstream to the 5-HT(3) receptor-mediated inhibition of the aortic but not carotid cardiac baroreflex response occurring during the defense reaction, therefore implying that baroreceptor afferent inputs may be differentially modulated depending on their origin. This differentiation may be useful for a better understanding of baroreflex dysfunction in disease-induced conditions.

Role of nucleus tractus solitarius 5-HT3 receptors in the defense reaction-induced inhibition of the aortic baroreflex in rats.

Different stressful conditions elicit a typical behavior called the defense reaction. Our aim was to determine whether 5-HT3 receptors in the nucleus tractus solitarius (NTS) are involved in 1) the inhibition of the baroreflex bradycardia and 2) the rise in blood pressure, which are known to occur during the defense reaction. In urethane-anesthetized rats, the defense reaction was elicited by electrical stimulation of the dorsomedial nucleus of the hypothalamus (DMH) or the dorsal part of the periaqueductal gray (dPAG). Direct electrical stimulation of the aortic depressor nerve was used to trigger the typical baroreflex responses. Aortic stimulation at high (100-150 microA) and low (50-90 microA) intensity produced a decrease in heart rate of -39 to -44% (relative to baseline, Group 1 responses, n = 113) and -19 to -24% (Group 2 responses, n = 43), respectively. In spontaneously breathing rats, Group 1 and Group 2 bradycardiac responses were inhibited during DMH (-75 +/- 4% and -96 +/- 4%, n = 38 and n = 11, respectively), as well as dPAG (-81 +/- 3% and -95 +/- 4%, n = 36 and n = 10, respectively) stimulation. The aortic baroreflex bradycardia was hardly affected by DMH or dPAG stimulation when bicuculline (5 pmol), a specific GABAA receptor antagonist, had previously been microinjected into the NTS. Likewise, NTS microinjections of granisetron, a specific 5-HT3 receptor antagonist, prevented, in a dose-dependent manner, the baroreflex bradycardia inhibition. In addition, intra-NTS granisetron did not affect the rise in blood pressure induced by either site stimulation. These data show that 5-HT3 receptors in the NTS are involved in the GABAergic inhibition of the aortic baroreflex bradycardia, but not in the rise in blood pressure, occurring during the defense reaction elicited by DMH or dPAG stimulation.

Long-term additive prognostic value of thallium-201 myocardial perfusion imaging over clinical and exercise stress test in low to intermediate risk patients : study in 1137 patients with 6-year follow-up.

BACKGROUND: The exercise treadmill test (ETT) and Tl201 single proton emission computed tomography (SPECT) are of short- to medium-term prognostic value in coronary heart disease. We assessed the long-term prognostic value of these tests in a large population of patients with low- to intermediate risk of cardiac events. METHODS AND RESULTS: One thousand one hundred thirty-seven patients (857 men, age 55+/-9 years) referred for typical (62.1%) or atypical (22.4%) chest pain, or suspected silent ischemia (15.5%), were followed up for 72+/-18 months. Overall mortality was higher after strongly positive (ST depression >2 mm, or >1 mm for a workload /=3 abnormal segments on SPECT, respectively (P<0.002). An abnormal SPECT was predictive of MI (P<0.001), whereas ETT was not. In multivariate analysis, SPECT was of incremental prognostic value over clinical and ETT data for predicting overall mortality and major cardiac events. CONCLUSIONS: The incremental predictive value of SPECT is maintained over 6 years and is particularly relevant after positive, strongly positive, and nondiagnostic ETT.

Cellular uptake mechanisms of 99mTcN-NOET in cardiomyocytes from newborn rats: calcium channel interaction.

BACKGROUND: Bis[N-ethoxy,N-ethyl(dithiocarbamato)]nitrido Tc (V) (TcN-NOET) is a new technetium complex proposed as a tracer of myocardial perfusion. However, its cellular uptake mechanisms are unknown, although membrane localization on rat heart preparations and preferential binding to polymorphonuclear neutrophils (PMNs) have been reported. Because of the central role of calcium in PMN actions, a relationship was hypothesized between this ion flux and TcN-NOET cellular uptake. METHODS AND RESULTS: The mechanisms of cellular uptake of TcN-NOET were investigated in newborn rat cardiomyocytes by study of the effect of calcium channel modulators on tracer binding. Nifedipine had no effect on tracer uptake at 1 minute. However, verapamil 0.1 micromol/L and diltiazem 0.5 micromol/L induced a 40% decrease in uptake. Conversely, Bay K 8644 0.25 micromol/L increased TcN-NOET uptake by 73%. Alterations in other membrane ion transports failed to modify tracer uptake, indicating the specificity of the relationship between TcN-NOET uptake and calcium channels. Kinetic studies indicated that cellular net accumulation of the tracer was slow (t1/2=28.5 minutes) and retention was prolonged (84% of initial activity retained after 120 minutes of washout). The energy dependence of TcN-NOET uptake was investigated after 60 minutes of metabolic inhibition by iodoacetic acid plus rotenone. The ATP decrease was not associated with reduction in tracer uptake at 1 minute (114.9+/-21.9% of control, P=NS). CONCLUSIONS: The decrease in uptake observed with verapamil and diltiazem, the increase with Bay K 8644, and the lack of effect with nifedipine suggest that TcN-NOET binds to L-type calcium channels in the open configuration, without entering cardiomyocytes. The kinetics of TcN-NOET accumulation and retention are slow, and the mechanism for cellular uptake is not energy-dependent. From a clinical point of view, the effect of concurrent treatment by calcium inhibitors on myocardial binding of TcN-NOET should be taken into account.

Biological evaluation of two iodine-123-labeled D-glucose acetals prepared as glucose transporter radioligands.

Two iodinated acetals of D-glucose, 4,6-(R)-O-(2'-iodoethylidene)-alpha, beta-D-glucose (1) and 4,6-(R)-O-(4'-iodobenzylidene)-alpha, beta-D-glucose (2), were prepared and their potential as suitable SPECT radioligands for imaging of glucose transporters was studied. Both are analogs of acetal D-glucose derivatives, which are known to bind to the exofacial sites of the glucose transport protein (GluT). To assess whether iodinated acetals 1 and 2 interacted with the glucose transporter, they were tested in vitro in human erythrocytes (GluT1) and neonatal rat cardiomyocytes (GluT4). The results indicated that 1 and 2 had a very low affinity for the glucose transporter and probably accumulated in cells. Study of their tissue distribution was carried out in the mouse in vivo: Both compounds showed fast tissue clearance with preferential renal elimination. It is concluded that iodinated acetals of D-glucose 1 and 2 are not suitable for GluT targeting in vivo.

Biological evaluation of two anomeric glucose analogues iodinated in position 6.

Two anomeric analogues of glucose labelled with 123 iodine in position 6, proposed as tracers of glucose transport in vivo, have been synthesized: alpha- and beta-methyl-6-deoxy-6-iodo-D-glucopyranoside (alpha MDIG and beta MDIG). The aim of this study was to determine whether these molecules interact with the glucose transporter and whether they could be used as tracers of glucose transport in vivo. The biodistribution of alpha MDIG and beta MDIG was studied in the mouse in vivo. To determine if these two anomers enter the cell via the glucose transporter, their uptake was measured in isolated perfused rat hearts, in human erythrocytes in suspension, and in cardiomyocytes of neonatal rat in culture. Both alpha MDIG and beta MDIG had similar repartitions in the mouse: myocardial uptake averaged 7% of the injected dose/g of organ at 2 min postinjection and alpha MDIG competed with D-glucose to enter the cells. Insulin produced a 123% increase of its uptake in isolated perfused rat hearts and a 100% increase in cardiomyocytes of neonatal rat in culture. alpha MDIG uptake was lowered in the presence of glucose transport inhibitors in each experimental model. An interaction between beta MDIG and glucose transporters was observed only in human erythrocytes in suspension. Only alpha MDIG interacts with the glucose transporter, and thus could be used to estimate glucose transport in vivo.

[123I]-6-deoxy-6-iodo-D-glucose (6DIG): a potential tracer of glucose transport.

A glucose analogue labelled with iodine-123 in position 6 has been synthesized: [123I]-6-deoxy-6-iodo-D-glucose (6DIG). The aim of this study was to examine its biological behaviour in order to assess whether it could be used to evaluate glucose transport with SPECT. To establish whether 6DIG enters the cells using the glucose transporter, four biological models have been used: human erythrocytes in suspension, neonatal rat cardiomyocytes in culture, isolated perfused rat hearts, and biodistribution in mice. 6DIG competed with D-glucose to enter the cells and its entry was increased by insulin and inhibited in the presence of cytochalasin B. The biological behaviour of 6DIG was similar to that of 3-O-methyl-D-glucose. 6DIG is a tracer of glucose transport which is very promising for clinical studies.

Effects of preoperative intentional hemodilution on the extravasation rate of albumin and fluid.

OBJECTIVE: To evaluate the effects of preoperative intentional hemodilution with 4% albumin solution on the extravasation rate of intravascular albumin and fluid in surgical patients. DESIGN: A prospective, randomized, clinical study. SETTING: University teaching hospital. PATIENTS: Two groups (control group [group 1] and hemodiluted group [group 2]) of 13 healthy patients were studied during a long-term (>4 hrs) surgical procedure. INTERVENTIONS: Autologous technetium-99m (99mTc)-labeled red blood cells and indium-oxine ((111)In)-labeled human serum albumin were injected intravenously during anesthesia at T = 0 min in the two groups for the determination of total blood volume and albumin diffusion space, respectively. In addition, body tetrapolar electrical impedance was used to assess extracellular fluid volume. In the hemodiluted group (group 2), 15 mL/kg of blood was withdrawn over 30 mins (T = 20 mins to T = 50 mins) and simultaneously replaced by an equal volume of 4% albumin solution (0.6 g/kg). MEASUREMENTS AND MAIN RESULTS: The albumin diffusion space, the colloid oncotic pressure, the plasma albumin concentration and the electrical impedance were measured before (T = 10 mins) and after (T = 60, 120, and 240 mins) hemodilution. Urine was collected from T = 10 mins to T = 240 mins. The total blood volume was calculated at T = 10 mins. No differences in the initial values were found between the two groups. In group 2, hemodilution (hematocrit 30 +/- 3%) resulted in a steeper increase in the albumin diffusion space (p < .05) and a progressive decrease in the body electrical impedance (p < .05). The extravasation rate of albumin was 0.052 +/- 0.007 mL/kg/min in group 2 vs. 0.038 +/- 0.020 mL/kg/min in group 1 (p < .05). The value of calculated plasma volume at T = 0 min did not shown any difference between the two groups. This value was then lower than expected in group 2, corresponding to a loss of plasma volume of >3 mL/kg. Urine output was significantly lower in group 2 than in group 1 (0.7 +/- 0.4 vs. 1.4 +/- 1.0 mL/min, respectively; p < .05). A comparable decrease in colloid oncotic pressure and in plasma albumin concentration was observed in both groups. CONCLUSIONS: These results suggest that preoperative hemodilution using 4% albumin on a 1:1 volume basis for blood substitution during a prolonged surgical procedure with reduced blood losses enhances the extravasation rate of albumin and fluid to the interstitial tissues, impeding the maintenance of isovolemia. These findings support the use of a volume of infused colloid solution higher than that of withdrawn blood during preoperative hemodilution.

Metabolic myocardial viability assessment with iodine 123-16-iodo-3-methylhexadecanoic acid in recent myocardial infarction: comparison with thallium-201 and fluorine-18 fluorodeoxyglucose.

The best test presently available to ascertain residual viability within an infarct-related area involves the use of fluorine-18 fluorodeoxyglucose (FDG) to detect the persistence of some cellular metabolism. Rest reinjection of thallium-201 is a less accurate alternative but is easy to perform. Iodinated fatty acids, which are used with standard gamma cameras, are proposed as markers of cellular metabolism. This study was performed to assess the value of 16-iodo-3-methylhexadecanoic acid (MIHA) as a marker of the residual cellular metabolism by comparison with FDG in patients with a recent myocardial infarction, and to evaluate its contribution compared with the 201Tl stress-redistribution-reinjection technique. Stress-redistribution-reinjection 201Tl imaging, rest MIHA imaging and glucose-loaded FDG imaging were performed in 22 patients with recent myocardial infarction. Out of the 628 myocardial segments obtained from the left ventricular analysis, 400 were hypoperfused (relative uptake <0.75 of maximum uptake on stress 201Tl imaging), 177 of which were severely hypoperfused (relative uptake <0.50). Receiver operating characteristic (ROC) curves for predicting metabolic myocardial viability with FDG were derived from the results in respect of (a) 201Tl activity during exercise, redistribution and reinjection and (b) MIHA uptake, using the two FDG thresholds most commonly considered to define metabolic viability (0.50 and 0.60). Analysis of the 400 hypoperfused segments demonstrated that 201Tl reinjection was the most accurate test in predicting the presence of myocardial viability (area under the ROI curves=0.85 and 0.86 at the 0.50 and 0.60 FDG thresholds, respectively; P<0.05 vs other tests). The global predictive values of MIHA and 201Tl reinjection were, respectively, 0.87 and 0.89 at the 0.50 FDG threshold (NS), and 0.82 and 0.87 at the 0.60 FDG threshold (NS). When only the 177 severely hypoperfused segments were considered, 201Tl reinjection remained the most accurate test (accuracy 0.84 at the 0.50 FDG threshold and 0.82 at the 0.60 FDG threshold), while the accuracy of MIHA decreased significantly (0.78 at the 0.50 FDG threshold and 0.73 at the 0.60 FDG threshold, P<0.05 vs 201Tl reinjection). In all circumstances, MIHA was less specific than 201Tl reinjection for the detection of metabolic viability. In conclusion, in patients with recent myocardial infarction, MIHA accurately detects the persistence of metabolic viability, but is not superior to 201Tl.

[Value and limitations of pulmonary scintigraphy/venous duplex Doppler echography in the management of pulmonary embolism]. / Intérêts et limites du couple scintigraphie pulmonaire/écho-Doppler veineux dans la gestion de l'embolie pulmonaire.

PURPOSE: To assess the accuracy of diagnostic strategy of pulmonary embolism (PE) based on clinical examination, lung scan and venous duplex US findings. METHODS: 1,819 patients have been included in a prospective study (mean age: 66, range: 6-102, F 54% H 46%) over a 13 month period. RESULTS: To decide the opportunity of anticoagulant therapy, lung scan alone is decisive in 30.6% of the cases. When taking into account clinical examination, lung scan and venous duplex US findings in a combined diagnostic strategy, a therapeutic decision can be made for 74.2% of the patients. The decisive characteristics of this strategy were influenced by two factor: age (therapeutic decision can be reached for 83% of the patients aged 30 to 50 vs 65% when they are over 85, p < 0.01); history of heart or pulmonary disease (therapeutic decision reached in 62% of the cases with history vs 78% without, p < 0.01). CONCLUSION: Pulmonary angiography seems theoretically necessary in less than 26% of the patients with suspected PE when they have undergone lung scan and venous duplex US. In this case, and when these strategies are not very decisive, it would be important to assess the diagnostic value of spiral CT scanning.

Characterization of 6-deoxy-6-iodo-D-glucose: a potential new tool to assess glucose transport.

6-deoxy-6-iodo-D-glucose (6-DIG) was rapidly taken up by adipocytes. Insulin increased 6-DIG transport in adipocytes isolated from both rats and mice. This stimulation was more important in rat than in mouse adipocytes, in agreement with their respective amount of Glut 4 transporters. In two insulin resistant states, the biological behavior of 6-DIG and 3-O-methyl-D-glucose was similar. These results indicated that 6-DIG, which was transported into the cells via the glucose transporters, could be potentially useful to measure modifications of glucose transport.

[Evaluation of the diagnostic usefulness of CA125 immunoscintigraphy for ovarian carcinoma follow-up after treatment: contribution of this technique in Grenoble University Medical Center]. / Evaluation de l'utilité diagnostique de l'immunoscintigraphie au CA.125 dans le suivi des carcinomes du revêtement épithélial de l'ovaire après traitement: apport décisionnel de la technique au CHU de Grenoble.

Immunoscintigraphy using indium-111-labeled OC125 monoclonal antibody F(ab')2 fragments is a technic complementary of morphological imaging (i.e. ultrasonography and computed tomography). It allows early detection of recurrences of ovarian carcinomas. We performed immunoscintigraphy 30 times in 26 patients who previously underwent radical treatment for ovarian carcinoma, and were suspected to have a recurrence. Our purposes were appreciation of diagnostic accuracy of the method, and above all its impact on clinical decisions and evolution of the patients. There were, after reevaluation of the results, 18 true positives, 7 true negatives, 3 false negatives and 2 false positive cases (sensitivity 85.7%, specificity 77.8%). Bayesian analysis showed positive and negative predictive values of 86% and 87% when probability of recurrence a priori was 50%, and 80% and 58% when probability of recurrence a priori was 70%. The result of immunoscintigraphy contributed to clinical decisions in 24 cases out of 30, and led to a correct decision for the patient in 21 cases. Conversely, for the 6 cases in which the result has not been considered, to take this result into account would have been beneficial in 4 cases, but harmful in 2. Finally, survival tended to be longer when immunoscintigraphy was negative, which could be associated with a better prognosis. We conclude that OC125-immunoscintigraphy may be useful for ovarian carcinoma follow-up and may contribute to a better therapeutic strategy.