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In this study, the total phenolic and flavonoid contents (TPC and TFC), secondary metabolite composition (LC-HRMS/MS analyses) and antioxidant potential (DPPH, ABTS, GOR, CUPRAC, and phenanthroline assays) of Linum trigynum L. (LT) extracts were determined. Our results showed for the first time that the extracts (PE, CHCl3, AcOEt, and n-BuOH) of LT exert antioxidant activity. The AcOEt and n-BuOH extracts were the most antioxidant compared to the standards, and had a higher amount of TPC (323.51 ± 0.62; 229.98 ± 6.80 µg GAE/mL) and TFC (183.75 ± 1.17 and 157.50 ± 1.77 µg QE/mL), resectively. The high antioxidant properties of these extracts may be due to their major compounds (phenolic compounds) detected by LC-HRMS/MS analyses including flavonoids (40 compounds) and phenolic acids and derivatives (18 and 19 compounds, respectively). AcOEt and n-BuOH extracts of LT can be used as an excellent source of antioxidant phytochemicals to prevent or treat various diseases.

Introduction: – The invasive quantification of coronary flow reserve (CFR), the index of microcirculatory resistance (IMR), and fractional flow reserve (FFR) allows to assess coronary physiology. Although semi-conductor (CZT) SPECT myocardial perfusion reserve (MPR) has been previously compared with FFR, there are no data documenting the relationships between CZT SPECT MPR on one hand and CFR and/or IMR on the other hand. We assessed the performances of noninvasive CZT SPECT MPR in comparison with invasively determined FFR, CFR, and IMR. Methods: – Rest and dipyridamole-induced stress myocardial blood flow and MPR were quantified using 99m Tc-SestaMIBI and a Discovery NM 530c camera in 26 patients with suspected or known coronary artery disease who underwent conventional invasive coronary angiography. Thermodilution-derived resting and adenosine-induced hyperemic mean transit times, distal intracoronary pressures, and mean aortic pressures were assessed for the quantification of FFR, CFR, and IMR values. Results: – Only 2/35 vessels presented with a pathological (P =.02). The sensitivity, specificity, positive and negative predictive value, and accuracy of regional CZT SPECT MPR vs CFR were 69% [44-86%], 94% [74-100%], 91% [65-100%], 77% [56-90%], and 82% [65-93%], respectively. In territories without underlying CAD (n=32), CZT SPECT MPR values were significantly higher in those with CFR≥2 and IMRvs 1.6 [1.2-1.8]), P Conclusions: – CZT SPECT MPR presented a moderate, significant correlation with thermodilution CFR and good diagnostic performances for the detection of patients at high risk of cardiovascular events (low CFR and high IMR) in the absence of obstructive CAD.

International audience; PURPOSE:Insulin resistance is a key feature of the metabolic syndrome and type 2 diabetes, in which noninvasive assessment is not currently allowed by any methodology. We previously validated an iodinated tracer of glucose transport (6DIG) and a new methodology for the in vivo quantification of cardiac insulin resistance in rodents. The aim of this study was to investigate the safety, biodistribution, and radiation dosimetry of this method using I-6DIG in 5 healthy and 6 diabetic volunteers.METHODS:The collection of adverse effects (AEs) and medical supervision of vital parameters and biological variables allowed the safety evaluation. Biodistribution was studied by sequentially acquiring whole-body images at 1, 2, 4, 8, and 24 hours postinjection. The total number of disintegrations in each organ normalized to the injected activity was calculated as the area under the time-activity curves. Dosimetry calculations were performed using OLINDA/EXM.RESULTS:No major adverse events were observed. The average dose corresponding to the 2 injections of I-6DIG used in the protocol was 182.1 ± 7.5 MBq. A fast blood clearance of I-6DIG was observed. The main route of elimination was urinary, with greater than 50% of urine activity over 24 hours. No blood or urine metabolite was detected. I-6DIG accumulation mostly occurred in elimination organs such as kidneys and liver. Mean radiation dosimetry calculations indicated an effective whole-body absorbed dose of 3.35 ± 0.57 mSv for the whole procedure.CONCLUSIONS:I-6DIG was well tolerated in human with a dosimetry profile comparable to that of other commonly used iodinated tracers, thereby allowing further clinical development of the tracer.

NeoB is a radiotracer targeting the gastrin-releasing peptide receptor (GRPR), a G-protein–coupled receptor expressed in various cancers. The aim of the present study was to evaluate the biodistribution and efficacy of this new therapeutic agent in Gastrointestinal Stromal Tumors (GIST). Eighty-two SCID mice bearing GIST-882 tumors were employed. [177Lu]Lu-NeoB biodistribution was evaluated up to seven days by organ sampling (200 pmol/0.8 MBq, i.v.). For efficacy evaluation, mice received either saline, 400 pmol or 800 pmol of [177Lu]Lu-NeoB (37MBq, 1/w, 3 w, i.v.). SPECT/CT imaging was performed at 24 h, and tumor volume was determined up to 100 days. Elevated and specific [177Lu]Lu-NeoB uptake was found in the GIST tumor, as demonstrated by in vivo competition (19.1 ± 3.9 %ID/g vs. 0.3 ± 0.1 %ID/g at 4h). [177Lu]Lu-NeoB tumor retention (half-life of 40.2 h) resulted in elevated tumor-to-background ratios. Tumor volumes were significantly reduced in both treated groups (p &lt, 0.01), even leading to complete tumor regression at the 400 pmol dose. [177Lu]Lu-NeoB exhibited excellent pharmacokinetics with elevated and prolonged tumor uptake and low uptake in non-target organs such as pancreas. The potential of this new theragnostic agent in different indications, including GIST, is under evaluation in the FIH [177Lu]Lu-NeoB clinical trial.

The objective of this study was to determine the accuracy of right ventricular function (RVF) assessed by Cadmium Zinc Telluride ECG-gated SPECT equilibrium radionuclide angiocardiography (CZT-ERNA). Twenty-one consecutive patients with cardiomyopathy (aged 54 ± 19 years; 62% male) were included. RV ejection fraction (EF) and volumes were analyzed by CZT-ERNA and compared with values obtained by cardiac magnetic resonance imaging (CMR). Mean values were not different between CZT-ERNA and MRI for RVEF (48.1 ± 10.4% vs 50.8 ± 10.0%; P = .23). Significant correlations (P

Introduction Myocardial perfusion reserve (MPR) is a validated diagnostic and prognostic value by Positron Emission Tomography (PET) scans. However, PET availability stays limited in certain countries as France. Gamma cameras with cadmium-zinc telluride detector (CZT-SPECT) are more available and allow the evaluation of this MPR. However, there is no comparison of its results with the interventional diagnostic procedure. Method Twenty-seven patients with suspected of epicardial or microcirculatory coronary involvement were prospectively included. All patients benefited from an evaluation of the MPR by CZT SPECT as well as an interventional diagnostic procedure with measure of the Fractionnal Flow Reserve (FFR), coronary flow reserve (CRF) and index of microcirculation resistance (IMR). Correlation between MPR and CFR was measured and sensitivity and specificity to detect severe coronary microcirculation disease (CMVD) defined by FFR > 0.8, CFR 25. Results Coronary angiography was performed in 27 patients, with a complete functional evaluation (FFR, CFR, IMR) on 33 vessels. Two patients had significant stenosis (50-90% stenosis and FFR Conclusion MPR was correlated with CRF and presented satisfactory diagnostic performance to discriminate, in the absence of significant stenosis, patients free from patients with severe CMVD.

Objective In Genetic Absence Epilepsy Rats From Strasbourg (GAERSs), epileptogenesis takes place during brain maturation and correlates with increased mRNA expression of D3 dopamine receptors (D3R). Whether these alterations are the consequence of seizure repetition or contribute to the development of epilepsy remains to be clarified. Here, we addressed the involvement of the dopaminergic system in epilepsy onset in GAERSs. Methods Experiments were performed using rats at different stages of brain maturation from three strains according to their increasing propensity to develop absence seizures: nonepileptic control rats (NECs), Wistar Hannover rats, and GAERSs. Changes in dopaminergic neurotransmission were investigated using different behavioral and neurochemical approaches: autoradiography of D3R and dopamine transporter, single photon emission computed tomographic imaging, acute and chronic drug effects on seizure recordings (dopaminergic agonists and antagonists), quinpirole-induced yawns and dopamine synaptosomal uptake, microdialysis, brain tissue monoamines, and brain-derived neurotrophic factor quantification. Results Autoradiography revealed an increased expression of D3R in 14-day-old GAERSs, before absence seizure onset, that persists in adulthood, as compared to age-matched NECs. This was confirmed by increased yawns, a marker of D3R activity, and increased seizures when animals were injected with quinpirole at low doses to activate D3R. We also observed a concomitant increase in the expression and activity of the dopamine transporter in GAERSs before seizure onset, consistent with both lowered dopamine basal level and increased phasic responses. Significance Our data show that the dopaminergic system is persistently altered in GAERSs, which may contribute not only to behavioral comorbidities but also as an etiopathogenic factor in the development of epilepsy. The data suggest that an imbalanced dopaminergic tone may contribute to absence epilepsy development and seizure onset, as its reversion by a chronic treatment with a dopamine stabilizer significantly suppressed epileptogenesis. Our data suggest a potential new target for antiepileptic therapies and/or improvement of quality of life of epileptic patients.

Recent progress in breast cancer research has led to the identification of Vascular Cell Adhesion Molecule-1 (VCAM-1) as a key actor of metastatic colonization. VCAM-1 promotes lung-metastases and is associated with clinical early recurrence and poor outcome in triple negative breast cancer (TNBC). Our objective was to perform the in vivo imaging of VCAM-1 in mice models of TNBC. The Cancer Genomic Atlas (TCGA) database was analyzed to evaluate the prognostic role of VCAM-1 in TNBC. MDA-MB-231 (VCAM-1+) and control HCC70 (VCAM-1-) TNBC cells were subcutaneously xenografted in mice and VCAM-1 expression was assessed in vivo by single-photon emission computed tomography (SPECT) imaging using 99mTc-cAbVCAM1-5. Then, MDA-MB-231 cells were intravenously injected in mice and VCAM-1 expression in lung metastasis was assessed by SPECT imaging after 8 weeks. TCGA analysis showed that VCAM-1 is associated with a poor prognosis in TNBC patients. In subcutaneous tumor models, 99mTc-cAbVCAM1-5 uptake was 2-fold higher in MDA-MB-231 than in HCC70 (p < 0.01), and 4-fold higher than that of the irrelevant control (p < 0.01). Moreover, 99mTc-cAbVCAM1-5 uptake in MDA-MB-231 lung metastases was also higher than that of 99mTc-Ctl (p < 0.05). 99mTc-cAbVCAM1-5 is therefore a suitable tool to evaluate the role of VCAM-1 as a marker of tumor aggressiveness of TNBC.

International audience; OBJECTIVE:The two related tumor necrosis factor members a proliferation-inducing ligand (APRIL) and B-cell activation factor (BAFF) are currently targeted in autoimmune diseases as B-cell regulators. In multiple sclerosis (MS), combined APRIL/BAFF blockade led to unexpected exacerbated inflammation in the central nervous system (CNS) of patients. Here, we investigate the role of the APRIL/BAFF axis in the CNS.METHODS:APRIL expression was analyzed in MS lesions by immunohistochemistry. The in vivo role of APRIL was assessed in the murine MS model, experimental autoimmune encephalitis (EAE). Functional in vitro studies were performed with human and mouse astrocytes.RESULTS:APRIL was expressed in lesions from EAE. In its absence, the disease was worst. Lesions from MS patients also showed APRIL expression upon infiltration of macrophages. Notably, all the APRIL secreted by these macrophages specifically targeted astrocytes. The upregulation of chondroitin sulfate proteoglycan, sometimes bearing chondroitin sulfate of type E sugar moieties, binding APRIL, in reactive astrocytes explained the latter selectivity. Astrocytes responded to APRIL by producing a sufficient amount of IL-10 to dampen antigen-specific T-cell proliferation and pathogenic cytokine secretion. Finally, an intraspinal delivery of recombinant APRIL before disease onset, shortly reduced EAE symptoms. Repeated intravenous injections of recombinant APRIL before and even at disease onset also had an effect.INTERPRETATION:Our data show that APRIL mediates an anti-inflammatory response from astrocytes in MS lesions. This protective activity is not shared with BAFF. ANN NEUROL 2019;85:406-420.© 2019 American Neurological Association.

Introduction Atherosclerosis is associated with a worse prognosis in many diseases, but its impact in non-ischemic dilated cardiomyopathy (NIDCM) is not known. Purpose This study investigated the prognostic value of coronary atherosclerotic burden, as measured by Gensini score, in a cohort of NIDCM patients. Methods In total, 139 patients with left ventricular (LV) dysfunction due to NIDCM were classified according to both invasive coronary angiography (ICA) and cardiovascular magnetic resonance (CMR) imaging data in 3 subtypes of NIDCM: true NIDCM, NIDCM with bystander coronary artery disease (CAD) and NIDCM with bystander myocardial infarction (MI). Percentage, extent, location of fibrosis was assessed with CMR and coronary atherosclerotic burden by calculating Gensini score. Primary endpoint was a composite of cardiovascular mortality, non-fatal MI and revascularisation by percutaneous coronary intervention (PCI). Results Out of 139 patients (mean age 59.4 ± 14.7 years old, 74% male), there were 101 patients (73%) with true NIDCM, 30 patients (22%) with NIDCM and bystander MI and 8 patients (5%) with NIDCM and bystander MI. 6 patients (4.3%) died and 6 (4.3%) underwent PCI during a median follow-up of 34.2 ± 18 months ( Table 1 ). Gensini score predicted primary composite endpoint, in univariate and multivariate analysis, hazard ratio = 1.08, confidence interval 95% (1.034–1.13) P = 0.001, as well as a history of CAD, LV ejection fraction (LVEF) and age (P Conclusion Coronary atherosclerotic burden, as measured by Gensini score, is a new prognostic factor in NIDCM. Assessing this parameter improves risk stratification and could be used to help personalise treatment in this population ( Fig. 1 ).

Background Single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) provides valuable prognostic value. However, the risk stratification of patients with type 2 diabetes mellitus (T2D) remains suboptimal. Objectives We hypothesised that myocardial perfusion entropy (MPE) quantified from SPECT myocardial perfusion images may provide an incremental prognostic value in T2D patients independently from the routinely performed assessment of myocardial ischemia. Methods T2D patients with very high and high cardiovascular risk were studied (n = 166, 65 ± 12 years). Ischemia (> 10% of left ventricular area) was assessed by SPECT MPI. In addition, SPECT MPI was used for the quantification of rest and stress MPE. The primary endpoint was major adverse cardiac events (MACEs) defined as cardiac death, Q-wave myocardial infarction (MI) and myocardial revascularisation > 3 months after SPECT. Results Forty-six patients underwent MACEs over a median follow-up of 4.6 years. Significant differences in stress MPE were observed between patients with and without MACEs (4.19 ± 0.46 vs. 3.93 ± 0.39; P ≤ .01). By Kaplan–Meier analysis, the risk of MACEs was significantly higher in patients with higher stress MPE (log-rank P ≤ .01). Stress MPE and ischemia were significantly associated with the risk of MACEs (hazard ratio: 2.30 and 1.12, respectively, P ≤ .01 for both) after adjustment for clinical and imaging risk factors as identified from preliminary, univariate analysis and including age, hypertension, stress test and ischemia. The incremental prognostic value of MPE over clinical risk factors was quantified using nested models showing improved AIC, reclassification (global continuous Net Reclassification Improvement [NRI]: 54, global Integrated Discrimination Improvement [IDI]: 4.6%), discrimination (change in c-statistic: 0.69 vs. 0.74). Conclusions Stress MPE provided independent and incremental prognostic information for the prediction of MACEs in diabetic patients.

Background The risk assessment for ventricular arrhythmia in patients with ischemic cardiomyopathy is, at the present time, unspecific. Left ventricular (LV) entropy is a measure of myocardial heterogeneity derived from single photon emission computed tomography (SPECT). Purpose This study assesses the utility of LV entropy for predicting cardiovascular events in patients with ischemic cardiomyopathy. Methods Patients with ischemic cardiomyopathy referred for implantable cardioverter-defibrillator (ICD) implantation were included retrospectively. Their LV entropy was measured on SPECT. Patients were followed from implantable cardioverter-defibrillator placement to detect arrhythmic events (appropriate implantable cardioverter-defibrillator therapy and sustained ventricular arrhythmia), end-stage heart failure events (congestive heart failure, transplantation, or ventricular assist device placement), and cardiac death. Results Forty patients (mean age 68.1 ± 9.4 years, 75% men, LV ejection fraction 29.7 ± 4.6%) were followed for 22.8 ± 12.9 months. Of the forty patients, three (7.5%) experienced arrhythmic events, one died of advanced heart failure after receiving the appropriate shock, and three others (7.5%) experienced end-stage heart failure events. On univariate analysis, age (HR: 1.02 [0.99; 1.04]; P = 0.176); diabetes (HR: 0.30 [0.05; 1.68]; P = 0.17), CRT-D (HR: 0.06 [0.007; 0.53]; P = 0.01), NYHA class (HR: 7.6 [2.00; 29.5]; P = 0.003) and ischemia (HR: 1.07 [0.96; 1.18]; P = 0.19) were significant predictors of cardiac events. On multivariate analysis, CRT-D (HR: 0.06 [0.04; 0.89]; P = 0.04) remained a significant predictor of cardiac events. LV entropy was not a predictor of cardiac events. Conclusion In patients with ischemic cardiomyopathy, LV entropy measurement is not a predictor of life-threatening ventricular arrhythmia. However, CRT-D is a strong protector of ventricular arrhythmia in ischemic cardiomyopathy.

Introduction Coronary microvascular dysfunction (CMD) is associated with a higher rate of major adverse cardiovascular events (MACEs) in diabetic patients. Liraglutide, a glucagon-like peptide-1 analog, decreases MACEs and all-cause mortality in this population. Purpose The present paper aims to study the effects of liraglutide on heart function and myocardial perfusion entropy (MPE) as a surrogate marker of coronary microvascular dysfunction (CMVD) in a rat model of type-2 diabetes. Methods Thirty-nine rats were divided into three groups, control (CTL), diabetic (T2D) and liraglutide (DT2-LIR). T2D and T2D-LIR rats were fed a high-fat diet and injected with 35 mg/kg streptozotocin intra-peritoneally (IP) to induce diabetes. T2D-LIR rats were injected with a subcutaneous liraglutide solution for four weeks. Heart structure and function were assessed with trans-thoracic-doppler echocardiography and CMVD was assessed with a novel 201 Thallium SPECT-technique, measuring MPE, under stress conditions. Histological analysis was later performed. Results T2D rats had a significantly lower left ventricular (LV) ejection fraction (LVEF) versus CTL (64.5 ± 4.3% vs. 74.4 ± 9.2% P Conclusion Liraglutide is associated with an improvement in heart systolic function and reduced LV hypertrophy in type 2 diabetic rats but only has a small specific effect on CMVD.

International audience; Mesothelin is a cell-surface glycoprotein restricted to mesothelial cells overexpressed in several types of cancer, including triple-negative breast cancer not responding to trastuzumab or hormone-based therapies. Mesothelin-targeting therapies are currently being developed. However, the identification of patients potentially eligible for such a therapeutic strategy remains challenging. The objective of this study was to perform the radiolabeling and preclinical evaluation of 99mTc-A1 and 99mTc-C6, two antimesothelin single-domain antibody (sdAb)-derived imaging agents. Methods: A1 and C6 were radiolabeled with 99mTc and evaluated in vitro on recombinant protein and cells, as well as in vivo in xenograft mouse models of the triple-negative breast cancer cell lines HCC70 (mesothelin-positive) and MDA-MB-231 (mesothelin-negative). Results: Both 99mTc-A1 and 99mTc-C6 bound mesothelin with high affinity in vitro, with 99mTc-A1 affinity being 2.4-fold higher than that of 99mTc-C6 (dissociation constant, 43.9 ± 4.0 vs. 107 ± 16 nM, P < 0.05). 99mTc-A1 and 99mTc-C6 remained stable in vivo in murine blood (>80% at 2 h) and ex vivo in human blood (>90% at 6 h). In vivo 99mTc-A1 uptake (percentage injected dose) in HCC70 tumors was 5-fold higher than in MDA-MB-231 tumors and 1.5-fold higher than that of 99mTc-C6 (2.34% ± 0.36% vs. 0.48% ± 0.18% and 1.56% ± 0.43%, respectively, P < 0.01) and resulted in elevated tumor-to-background ratios. In vivo competition experiments demonstrated the specificity of 99mTc-A1 uptake in HCC70 tumors. Conclusion: Mesothelin-positive tumors were successfully identified by SPECT using 99mTc-A1 and 99mTc-C6. Considering its superior characteristics, 99mTc-A1 was selected as the most suitable tool for further clinical translation.

International audience; The addition of ezetimibe, an intestinal cholesterol absorption inhibitor, to statin therapy has recently shown clinical benefits in the Improved Reduction of Outcomes: Vytorin Efficacy International Trial by reducing low-density-lipoprotein (LDL) cholesterol levels more than statin therapy alone. Here, we investigated the mechanisms by which inhibition of intestinal cholesterol absorption might contribute to the clinically observed reduction in cardiovascular events by evaluating its effect on inflammatory plaque development in apolipoprotein E-/- mice. Methods: Apolipoprotein E-/- mice were fed the Paigen diet (1.25% cholesterol, 0.5% cholic acid, and 15% fat) without or with ezetimibe (7 mg/kg/d) for 6 wk. In a first set of mice (n = 15), we intravenously injected 3H-cholesteryl oleate-labeled human LDL to test whether ezetimibe promotes LDL-derived cholesterol fecal excretion. In a second set (n = 20), we used the imaging agent 99mTc-cAbVCAM1-5 to evaluate expression of an inflammatory marker, vascular cell adhesion molecule 1 (VCAM-1), in atherosclerotic plaques. In a third set (n = 21), we compared VCAM-1 expression with 99mTc-cAbVCAM1-5 uptake in various tissues. Results: Mice treated with ezetimibe showed a 173% higher LDL-cholesteryl ester plasma disappearance rate (P < 0.001 vs. control) after 3H-cholesteryl oleate-labeled LDL injection. At 96 h after injection, the hepatic fraction of 3H-tracer was 61% lower in mice treated with ezetimibe (P < 0.001). Meanwhile, LDL-derived 3H-cholesterol excretion in the feces was 107% higher (P < 0.001). The antiatherogenic effect of ezetimibe monitored by 99mTc-cAbVCAM1-5 SPECT showed a 49% reduction in aortic tracer uptake (percentage injected dose per cubic centimeter, 0.95 ± 0.04 vs. 1.87 ± 0.11; P < 0.01). In addition to hypercholesterolemia, the proinflammatory Paigen diet significantly increased VCAM-1 expression with respect to the control group in various tissues, including the aorta, and this expression correlated strongly with 99mTc-cAbVCAM1-5 uptake (r = 0.75; P < 0.05). Conclusion: Inhibition of intestinal cholesterol absorption with ezetimibe promotes antiatherosclerotic effects through increased LDL cholesterol catabolism and LDL-derived cholesterol fecal excretion and reduces inflamed atherosclerotic plaques. These mechanisms may contribute to the benefits of adding ezetimibe to a statin therapy.

International audience; Mouse models of atherosclerosis are extensively being used to study the mechanisms of atherosclerotic plaque development and the results are frequently extrapolated to humans. However, major differences have been described between murine and human atherosclerotic lesions and the determination of similarities and differences between these species has been largely addressed recently. This study takes over and extends previous studies performed by our group and related to the biomechanical characterization of both mouse and human atherosclerotic lesions. Its main objective was to determine the distribution and amplitude of mechanical stresses including peak cap stress (PCS) in aortic vessels from atherosclerotic apoE(-/-) mice, in order to evaluate whether such biomechanical data would be in accordance with the previously suggested lack of plaque rupture in this model. Successful finite element analysis was performed from the zero-stress configuration of aortic arch sections and mainly indicated (1) the modest role of atherosclerotic lesions in the observed increase in residual parietal stresses in apoE(-/-) mouse vessels and (2) the low amplitude of murine PCS as compared to humans. Overall, the results from the present study support the hypothesis that murine biomechanical properties and artery size confer less propensity to rupture for mouse lesions in comparison with those of humans.

Mesothelin is a membrane-associated protein overexpressed in pancreatic ductal adenocarcinoma (PDAC). Some mesothelin-targeted therapies are in clinical development but the identification of patients eligible for such therapies is still challenging. The objective of this study was to perform the imaging of mesothelin in mice models of PDAC with a technetium-labeled anti-mesothelin single-domain antibody (99mTc-A1). Methods: The Cancer Genomic Atlas (TCGA) database was used to determine the prognostic role of mesothelin in PDAC. 99mTc-A1 was evaluated both in vitro in PDAC cells (SW1990 and AsPC-1) and in vivo in an experimental model of mesothelin-expressing PDAC (AsPC-1) in mice. Results: TCGA analysis showed that PDAC patients with high mesothelin expression had a shorter overall survival (P = 0.00066). The binding of 99mTc-A1 was 2.1-fold greater in high-mesothelin-expressing AsPC-1 cells when compared to moderate-mesothelin-expressing SW1990 cells (p < 0.05). In vivo, the 99mTc-A1 uptake was 3.5-fold higher in AsPC-1-derived tumors as compared to a technetium-labeled irrelevant antibody (99mTc-Ctl) (p < 0.01). Conclusions: 99mTc-A1 accurately allows imaging of mesothelin-expressing experimental PDAC tumors. Our experiments paved the way for the development of a companion test for mesothelin-targeted therapies.

Vascular cell adhesion molecule 1 (VCAM-1) plays a major role in the chronic inflammatory processes involved in vulnerable atherosclerotic plaque development. We previously showed that the (99m)Tc-labeled major histocompatibility complex 1-derived peptide B2702p bound specifically to VCAM-1 and allowed the ex vivo imaging of atherosclerotic lesions in Watanabe heritable hyperlipidemic rabbits. However, B2702p target-to-background ratio was suboptimal for the in vivo imaging of VCAM-1 expression in atherosclerotic lesions. To improve the target-to-background ratio, 20 derivatives of B2702p (B2702p1-B2702p20) were synthesized using the alanine scan methodology. We hypothesized that (99m)Tc-radiolabeled B2702p derivatives might allow the molecular imaging of VCAM-1 expression in an experimental model of atherosclerosis.A mouse model of focal atherosclerotic plaque development induced by left carotid artery ligation in apolipoprotein E double-knockout (ApoE(-/-)) mice was used (n = 82). (99m)Tc-B2702p and (99m)Tc-B2702p1-(99m)Tc-B2702p20 were injected intravenously in anesthetized animals 3 wk after the ligation. Whole-body planar imaging was performed for 3 h. SPECT imaging of 6 additional ligated ApoE(-/-) mice was also performed with (99m)Tc-B2702p1. The animals were then euthanized, and the biodistribution of (99m)Tc-labeled peptides was evaluated by γ-well counting of excised organs. Expression of VCAM-1 in the ligated and contralateral carotid arteries was evaluated by immunohistology.Robust VCAM-1 immunostaining was observed in the left carotid atherosclerotic lesions as a consequence of artery ligation, whereas no VCAM-1 expression was detected in the contralateral carotid artery. Among all evaluated peptides, (99m)Tc-B2702p1 exhibited the most favorable properties. By γ-well counting, there was a significant 2.0-fold increase in the (99m)Tc-B2702p1 left-to-right carotid artery activity ratio (2.6 ± 0.6) and a 3.4-fold increase in the left carotid-to-blood activity ratio (1.4 ± 0.4) in comparison to (99m)Tc-B2702p (1.3 ± 0.2 and 0.4 ± 0.1, respectively, P0.05 for both comparisons). Similarly, planar image quantification indicated a higher left-to-right carotid activity ratio in (99m)Tc-B2702p1- than in (99m)Tc-B2702p-injected mice (1.2 ± 0.1 vs. 1.0 ± 0.0, respectively, P0.05). Finally, a significantly higher (99m)Tc-B2702p1 activity in the left than in the right carotid artery was observed by SPECT imaging (2.2 ± 0.4 vs. 1.4 ± 0.3 cpm/mm(2)/injected dose, respectively, P0.05).(99m)Tc-B2702p1 is a potentially useful radiotracer for the in vivo molecular imaging of VCAM-1 expression in atherosclerotic plaques.

International audience; Unmixing is often a necessary step to analyze 2D SPECT image sequence. However, factor analysis of dynamic sequences (FADS), the commonly used method for unmixing SPECT sequences, suffers from non-uniqueness issue. Optimization-based methods were developed to overcome this issue. These methods are effective but need improvement when the mixing is important or with very low SNR. In this paper, a new objective function using soft spatial prior knowledge is developed. Comparison with previous methods, efficiency and robustness to the choice of priors are illustrated with tests on synthetic dataset. Results on 2D SPECT sequences with high level of noise are also presented and compared.

AIMS: Positron emission tomography-computed tomography (PET-CT) is a highly sensitive clinical molecular imaging modality to study atherosclerotic plaque biology. Therefore, we sought to develop a new PET tracer, targeting vascular cell adhesion molecule (VCAM)-1 and validate it in a murine atherosclerotic model as a potential agent to detect atherosclerotic plaque inflammation. METHODS AND RESULTS: The anti-VCAM-1 nanobody (Nb) (cAbVCAM-1-5) was radiolabelled with Fluorine-18 ((18)F), with a radiochemical purity of >98%. In vitro cell-binding studies showed specific binding of the tracer to VCAM-1 expressing cells. In vivo PET/CT imaging of ApoE(-/-) mice fed a Western diet or control mice was performed at 2h30 post-injection of [(18)F]-FB-cAbVCAM-1-5 or (18)F-control Nb. Additionally, plaque uptake in different aorta segments was evaluated ex vivo based on extent of atherosclerosis. Atherosclerotic lesions in the aortic arch of ApoE(-/-) mice, injected with [(18)F]-FB-anti-VCAM-1 Nb, were successfully identified using PET/CT imaging, while background signal was observed in the control groups. These results were confirmed by ex vivo analyses where uptake of [(18)F]-FB-cAbVCAM-1-5 in atherosclerotic lesions was significantly higher compared with control groups. Moreover, uptake increased with the increasing extent of atherosclerosis (Score 0: 0.68 ± 0.10, Score 1: 1.18 ± 0.36, Score 2: 1.49 ± 0.37, Score 3: 1.48 ± 0.38%ID/g, Spearman's r(2) = 0.675, P < 0.0001). High lesion-to-heart, lesion-to-blood, and lesion-to-control vessel ratios were obtained (12.4 ± 0.4, 3.3 ± 0.4, and 3.1 ± 0.6, respectively). CONCLUSION: The [(18)F]-FB-anti-VCAM-1 Nb, cross-reactive for both mouse and human VCAM-1, allows non-invasive PET/CT imaging of VCAM-1 expression in atherosclerotic plaques in a murine model and may represent an attractive tool for imaging vulnerable atherosclerotic plaques in patients.

The addition of ezetimibe, an intestinal cholesterol absorption inhibitor, to statin therapy has recently shown clinical benefits in the Improved Reduction of Outcomes: Vytorin Efficacy International Trial by reducing low-density-lipoprotein (LDL) cholesterol levels more than statin therapy alone. Here, we investigated the mechanisms by which inhibition of intestinal cholesterol absorption might contribute to the clinically observed reduction in cardiovascular events by evaluating its effect on inflammatory plaque development in apolipoprotein E

Maurocalcine (MCa) is the first natural cell penetrating peptide to be discovered in animal venom. In addition to the fact that it represents a potent vector for the cell penetration of structurally diverse therapeutic compounds, MCa also displays several distinguishing features that make it a potential peptide of choice for clinical and biotechnological applications. The aim of the present study was to gain new information about the properties of MCa in vivo in order to delineate the future potential applications of this vector. For this purpose, two analogues of this peptide with (Tyr-MCa) and without (Lin-Tyr-MCa) disulfide bridges were synthesized, radiolabeled with 125I, and their in vitro stabilities were first evaluated in mouse blood. The results indicated that 125I-Tyr-MCa was stable in vitro and that the disulfide bridges conferred a competitive advantage for the stability of peptide. Following in vivo injection in mice, 125I-Tyr-MCa targeted peripheral organs with interesting quantitative differences and the main route of peptide elimination was renal.

Background: Intestinal cholesterol absorption inhibitor ezetimibe (EZE) added to a statin therapy has demonstrated benefits in the IMPROVE-IT trial by further reducing LDL-cholesterol levels than statin therapy alone. We investigated the mechanisms by which EZE could contribute to cardiovascular events reduction in apolipoprotein E knock-out (apoE ko) mice. Methods: ApoE ko mice were fed a Paigen diet without (control) or with EZE (7mg/kg/day) for 6 weeks. To evaluate the effects of EZE on LDL-cholesterol metabolism and excretion, a first set of mice was injected intravenously with 3 H-cholesteryl oleate labeled human LDL. A second set of mice was used for in vivo SPECT/CT imaging of 99m Tc-cAbVCAM1-5, a single domain antibody directed against the Vascular Cell Adhesion Molecule-1 (VCAM-1), which was used as a marker of inflamed atherosclerotic plaques. The same mice were sacrificed for autoradiography and histology of aortic atherosclerotic plaques. Results: Compared with control, EZE treatment for 6 weeks induced a significant 41% and 65% reduction in plasma total cholesterol levels and atherosclerotic plaque area, respectively. After injection of 3 H-cholesteryl oleate labeled human LDL, mice treated with EZE showed a 173% higher LDL-cholesteryl ester catabolism (p3 H-tracer hepatic recovery was reduced by 61% with EZE (p3 H-tracer excretion in the feces was increased by 107% in the fecal cholesterol fraction (p After intravenous injection of 99m Tc-cAbVCAM1-5, mice treated with EZE also showed a significant 52% reduction in aortic uptake, which was confirmed by significant reduction in tracer uptake in ex vivo biodistribution and autoradiography analysis. Conclusion: EZE promotes anti-atherosclerotic effects through increased LDL-cholesterol catabolism and LDL-derived cholesterol fecal excretion, and reduced inflamed atherosclerotic plaques. These mechanisms may contribute to the benefits of adding EZE to a statin therapy.

Introduction RNA interference is efficient in in vitro studies, and appears as a therapeutic tool of major clinical interest. Nevertheless, the clinical utilisation of siRNAs is restrained by the poor availability of biodistribution data on this new class of pharmaceutics. This study aimed at defining the biodistribution and pharmacokinetics properties of an siRNA directed to the Casein Kinase-2 beta (CK2β) subunit, a potential target in cancer therapy. Methods Four CK2β siRNAs were chemically modified on each extremity of sense or anti-sense strand and radioiodinated. The biodistribution of each entity was analysed in glioblastoma-bearing mice using nuclear imaging and compared to a control GFP siRNA. Results The labelling process was associated with preservation of interference activity, except when applied to the 5 ' antisense terminus. Radioactivity was predominantly observed in organs of the excretory system after intravenous administration: liver, kidneys and bladder. Tumor/Contralateral muscle ratio showed significant differences depending on the labelling site. Activity associated with CK2β 5 ' s was quite constant over 2hours, while CK2β 3 ' as activity decreased by 40% in tumor. Finally, synchrotron X-ray analysis showed that CK2β 3 ' s is more abundant in tumor than in liver, brain or muscle, and uniformly distributed between intra- and extracellular compartments. Conclusions In this study, we highlighted the large influence of siRNAs radiolabelling position on their biodistribution and pharmacokinetic profiles, and proposed a systematic approach for the imaging of all siRNAs of clinical interest.

International audience; Previous works have shown the interest of naturally fluorescent proflavine derivatives to label Abeta deposits in vitro. This study aimed to further characterize the properties of the proflavine 3-acetylamino-6-[3-(propargylamino)propanoyl]aminoacridine (COB231) derivative as a probe. This compound was therefore evaluated on human post-mortem and mice brain slices and in vivo in 18-month-old triple transgenic mice APPswe, PS1M146V and tauP301L (3xTgAD) mice presenting the main characteristics of Alzheimer's disease (AD). COB231 labelled amyloid plaques on brain slices of AD patients, and 3xTgAD mice at 10 and 0.1 μM respectively. However, no labelling of the neurofibrillary tangle-rich areas was observed either at high concentration or in the brain of fronto-temporal dementia patients. The specificity of this mapping was attested in mice using Thioflavin S and IMPY as positive controls of amyloid deposits. After intravenous injection of COB231 in old 3xTgAD mice, fluorescent amyloid plaques were detected in the cortex and hippocampus, demonstrating COB231 blood–brain barrier permeability. We also controlled the cellular localization of COB231 on primary neuronal cultures and showed that COB231 accumulates into the cytoplasm and not into the nucleus. Finally, using a viability assay, we only detected a slight cytotoxic effect of COB231 (< 10%) for the highest concentration (100 μM).

Abdominal aortic aneurysms (AAA) usually progress asymp-tomatically and are undetected until rupture occurs. Onceruptured, the mortality rate of AAA is about 80 %. Amongall patients with ruptured AAA, about one-third die withoutreachinghospital,andaboutanotherquarterreachhospitalbutdie prior to surgical intervention. Among the remaining pa-tients (about 40 %) surviving AAA rupture long enough tobenefit from surgical intervention, the perioperative mortalityhas historically reached about 50 % [1], a value that hashowever recently decreased owing to the introduction ofendovascular repair [2]. On the other hand, elective AAArepair has a much lower in-hospital mortality rate, with re-cently reported values of 1.3 % and 4.7 % for endovascularand open surgical repair, respectively [3], thereby stronglyemphasizingtheneedforscreeningandidentificationofthosepatients with prone-to-rupture AAA.The crude estimate of AAA diameter remains the mostwidely used predictive risk factor for AAA rupture and thesole therapeutic management criterion. Indeed, in both the2014EuropeanSocietyofCardiologyandthe2011AmericanCollege of Cardiology/American Heart Association guide-lines, aortic repair is a class I indication if the AAA diameterexceeds55mm[4,5].However,thelimitationsofthisparam-eter are well acknowledged, and it is therefore unanimouslyagreed that a more robust noninvasive predictor of the indi-vidual riskofAAA rupture is required. Althoughbeing muchless documented than atherogenesis, the current knowledgeregarding the pathophysiology of AAA indicates that parietalinflammation, matrix degradation and smooth muscle cellapoptosis are required for AAA pathogenesis [6]. FDG hasbeen suggested as a potentially useful agent for the molecularimaging of vascular inflammation due to the elevated carbo-hydratemetabolismofextravasatedinflammatorycells[7].Assuch, the tracer has been extensively evaluated in both theexperimentalandclinicalsettingsforthenoninvasiveimagingof inflammatory processes in vulnerable atherosclerotic le-sions as well as in AAA.In the multicentre study by Barwick and colleagues pub-lished in this issue of the European Journal of Nuclear Med-icine&MolecularImaging[8],theauthorsusedPETimagingof FDG uptake to retrospectively compare the metabolicactivity in the abdominal aortic wall of 151 patients withAAA (mean aortic diameter, 50±13 mm) with that of 159individuals with no AAA (mean aortic diameter, 21±3 mm)and matched for age, sex, diabetes, smoking status, statin useand indication for PET/CT. This cohort is the largest so farused for the comparison of FDG uptake between AAA andnormal vessels in well-matched patients. FDG uptake wasanalysed by semiquantitative visual scoring as well as quan-titatively using SUVmax and target to background ratiosutilizing mediastinal blood pool or descending thoracic aortaactivities for normalization.Althoughthe retrospective natureand the design of the study limit the conclusions that can bedrawn with respect to the potential of FDG for predictingAAA growth or rupture, the results unequivocally show thatthere was no correlation between AAA size and FDG uptakeand that there was no statistically significant difference inFDG uptake between AAA and normal abdominal aortas.The study by Barwick et al. therefore joins the ranks ofthose suggesting the suboptimal usefulness of FDG for AAAevaluation, which face the ranks of previously publishedstudies that reached opposite conclusions by suggesting the

Objectives The aim of this study was to determine the diagnostic accuracy of stress thallium-201/rest technetium-99m sequential dual-isotope high-speed myocardial perfusion imaging (DI-HS-MPI) against invasively determined fractional flow reserve (FFR) and to establish the correlation between myocardium at risk defined by using the invasive BARI-score and DI-HS-MPI. Background Relatively few studies have compared the diagnostic performance of new Cadmium Zinc Telluride - cameras versus FFR. Methods Fifty-four patients referred for angiography underwent DI-HSMPI. Perfusion was scored visually by summed stress score (SSS) on a patient and coronary territory basis, and ischemic burden was calculated by quantitative segmentation of the extent of ischemia. Significant coronary artery disease (CAD) was defined by the presence of ≥90% stenosis/occlusion or fractional flow reserve ≤0.80 in vessels >2mm. The relation between FFR and perfusion was determined for each vascular zone. The BARI-score was calculated from the coronary angiograms to quantify the myocardium at risk. Results FFR was measured in 70 of 162 coronary vessels; Vessels FFR measured per patient was 1.3±0.57. Sensitivity, specificity, and diagnostic accuracy of MPI for the detection of significant CAD were 92%, 88%, and 90% by coronary territory and 87%, 93%, and 92%, on a patient basis. The area under the summary receiver-operating characteristic at the patient level was 0.94 (95% CI: 0.88 to 1) and 0.90 (95% CI: 0.83 to 0.97) at the artery and territory levels, respectively. The mean ischemic burden for MPI and BARI-score showed a strong correlation between techniques (r=0.71, P Conclusions Stress thallium-201/rest technetium-99m sequential DI-HSMPI accurately detects functionally significant CAD as defined by using FFR and provides an assessment of ischemic burden in agreement with the invasive BARI-score.

De nombreuses pathologies sont associees aux anomalies du metabolisme du glucose ou aux perturbations de son transport (diabete de type 2 ou insulino-resistance). L'etat pre-diabetique est caracterise par un etat d'insulino-resistance ou, en d'autres termes, par un defaut de transport de glucose vers les tissus insulino-sensibles. tels que les muscles et le tissu adipeux. La modelisation mathematique des donnees experimentales peut etre une excellente methode pour etudier les mecanismes impliques dans le phenomene biologique concerne. Ainsi, a partir d'une representation symbolique comme la modelisation compartimentale, il est possible de developper une base theorique pour l'observation et de considerer les experiences les mieux adaptees pour l'etude. Nous avons montre, avec des modeles compartimentaux, que le [ 123 I]-6-deoxy-6-iodo-D-glucose (6-DIG), valide comme traceur du transport du glucose in vitro, peut permettre la verification de cette anomalie de transport. Pour mesurer cette insulino-resistance, nous avons estime les coefficients de transfert fractionnel du 6-DIG du sang vers les differents organes de l'etude. Nous avons realise plusieurs etudes avant d'arriver a un modele satisfaisant et une attention toute particuliere a ete portee a la precision des parametres estimes, afin de choisir le meilleur modele. Les resultats ont montre qu'en associant les donnees experimentales obtenues avec les activites du 6-DIG et un modele mathematique adapte, des parametres discriminants (coefficients de transfert fractionnel) entre les deux groupes, rats temoins et insulinoresistants, peuvent etre degages.

International audience; L-Maurocalcine (L-MCa) is the first reported animal cell-penetrating toxin. Characterizing its cell penetration properties is crucial considering its potential as a vector for the intracellular delivery of drugs. Radiolabeling is a sensitive and quantitative method to follow the cell accumulation of a molecule of interest. An L-MCa analog containing an additional N-terminal tyrosine residue (Tyr-L-MCa) was synthesized, shown to fold and oxidize properly, and successfully radioiodinated to (125)I-Tyr-L-MCa. Using various microscopy techniques, the average volume of the rat line F98 glioma cells was evaluated at 8.9 to 18.9×10(-7)μl. (125)I-Tyr-L-MCa accumulates within cells with a dose-dependency similar to the one previously published using 5,6-carboxyfluorescein-L-MCa. According to subcellular fractionation of F98 cells, plasma membranes keep less than 3% of the peptide, regardless of the extracellular concentration, while the nucleus accumulates over 75% and the cytosol around 20% of the radioactive material. Taking into account both nuclear and cytosolic fractions, cells accumulate intracellular concentrations of the peptide that are equal to the extracellular concentrations. Estimation of (125)I-Tyr-L-MCa cell entry kinetics indicate a first rapid phase with a 5min time constant for the plasma membrane followed by slower processes for the cytoplasm and the nucleus. Once inside cells, the labeled material no longer escapes from the intracellular environment since 90% of the radioactivity remains 24h after washout. Dead cells were found to have a lower uptake than live ones. The quantitative information gained herein will be useful for better framing the use of L-MCa in biotechnological applications. This article is part of a Special Issue entitled: Calcium Signaling in Health and Disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.

International audience; Background - The great clinical potential of myocardial β-AR imaging has been shown by recent studies evaluating the β-AR specific, non selective agent [11C]-CGP12177 in the setting of idiopathic dilated cardiomyopathy and myocardial infarction. However, the short half-life of 11C hampers the potential of [11C]-CGP12177 for routine clinical use. AMI9 is an analog of the β-adrenoceptor ligand practolol that can readily be labeled using radioactive isotopes of iodine. The present study was aimed at characterizing the in vitro, ex vivo, and in vivo β-AR binding properties of [125I]-AMI9. Methods and Results – Newborn rat cardiomyocytes were used for saturation and kinetic binding assays as well as for displacement and competition experiments. Isolated perfused rat hearts were used to evaluate the pharmacological activity of AMI9. The in vivo kinetics of [125I]-AMI9 were studied using biodistribution experiments in mice. [125I]-AMI9 displayed high specific affinity for β-AR with no β-AR subtype selectivity (KD, 5.6±0.3 nM; Bmax, 231±7 fmol/mg of protein). AMI9 potently inhibited the inotropic effects of isoproterenol. The early in vivo cardiac and lung activities of [125I]-AMI9 compared favorably with those of the clinically validated tracer CGP12177. Conclusions – Iodine-labeled AMI9 is a promising agent for the molecular imaging of myocardial β-AR density.

UNLABELLED: (99m)Tc-cAbVCAM1-5, a single-domain antibody fragment directed against mouse or human vascular cell adhesion molecule 1 (VCAM-1), recently has been proposed as a new imaging agent for the detection of inflamed atherosclerotic lesions. Indeed, in a mouse model of atherosclerosis, (99m)Tc-cAbVCAM1-5 specifically bound to VCAM-1-positive lesions, thereby allowing their identification on SPECT images. The purpose of the present study was to investigate (99m)Tc-cAbVCAM1-5 imaging sensitivity using a reference statin therapy. METHODS: Thirty apolipoprotein E-deficient mice were fed a western-type diet. First, the relationship between the level of VCAM-1 expression and (99m)Tc-cAbVCAM1-5 uptake was evaluated in 18 mice using immunohistochemistry and autoradiography. Second, longitudinal SPECT/CT imaging was performed on control (n = 9) or atorvastatin-treated mice (0.01% w/w, n = 9). RESULTS: (99m)Tc-cAbVCAM1-5 uptake in atherosclerotic lesions correlated with the level of VCAM-1 expression (P < 0.05).Atorvastatin exerted significant antiatherogenic effects, and (99m)Tc-cAbVCAM1-5 lesion uptake was significantly reduced in 35-wk-old atorvastatin-treated mice, as indicated by ex vivo γ-well counting and autoradiography (P < 0.05). SPECT imaging quantification based on contrast-enhanced CT was reproducible (interexperimenter intraclass correlation coefficient, 0.97; intraexperimenter intraclass correlation coefficient, 0.90), and yielded results that were highly correlated with tracer biodistribution (r = 0.83; P < 0.0001). Therefore, reduced (99m)Tc-cAbVCAM1-5 uptake in atorvastatin-treated mice was successfully monitored noninvasively by SPECT/CT imaging (0.87 ± 0.06 vs. 1.11 ± 0.09 percentage injected dose per cubic centimeter in control group, P < 0.05). CONCLUSION: (99m)Tc-cAbVCAM1-5 imaging allowed the specific, sensitive, and reproducible quantification of VCAM-1 expression in mouse atherosclerotic lesions. (99m)Tc-cAbVCAM1-5 therefore exhibits suitable characteristics for the evaluation of novel antiatherogenic agents.

In vivo imaging of GABAA receptors is essential for the comprehension of psychiatric disorders in which the GABAergic system is implicated. Small animal SPECT provides a modality for in vivo imaging of the GABAergic system in rodents using [(123)I]Iomazenil, an antagonist of the GABAA receptor. The goal of this work is to describe and evaluate different quantitative reference tissue methods that enable reliable binding potential (BP) estimations in the rat brain to be obtained.Five male Sprague-Dawley rats were used for [(123)I]Iomazenil brain SPECT scans. Binding parameters were obtained with a one-tissue compartment model (1TC), a constrained two-tissue compartment model (2TCc), the two-step Simplified Reference Tissue Model (SRTM2), Logan graphical analysis and analysis of delayed-activity images. In addition, we employed factor analysis (FA) to deal with noise in data.BPND obtained with SRTM2, Logan graphical analysis and delayed-activity analysis was highly correlated with BPF values obtained with 2TCc (r=0.954 and 0.945 respectively, p0.0001). Equally significant correlations were found between values obtained with 2TCc and SRTM2 in raw and FA-denoised images (r=0.961 and 0.909 respectively, p0.0001). Scans of at least 100min are required to obtain stable BPND values from raw images while scans of only 70min are sufficient from FA-denoised images. These images are also associated with significantly lower standard errors of 2TCc and SRTM2 BP values.Reference tissue methods such as SRTM2 and Logan graphical analysis can provide equally reliable BPND values from rat brain [(123)I]Iomazenil SPECT. Acquisitions, however, can be much less time-consuming either with analysis of delayed activity obtained from a 20-minute scan 50min after tracer injection or with FA-denoising of images.

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 μmol/L and diltiazem 0.5 μmol/L induced a 40% decrease in uptake. Conversely, Bay K 8644 0.25 μmol/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 (t 1/2 =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.

International audience; The industrial development of active immunotherapy based on live-attenuated bacterial vectors has matured. We developed a microsyringe for antigen delivery based on the type III secretion system (T3SS) of P. aeruginosa. We applied the "killed but metabolically active" (KBMA) attenuation strategy to make this bacterial vector suitable for human use. We demonstrate that attenuated P. aeruginosa has the potential to deliver antigens to human antigen-presenting cells in vitro via T3SS with considerable attenuated cytotoxicity as compared with the wild-type vector. In a mouse model of cancer, we demonstrate that this KBMA strain, which cannot replicate in its host, efficiently disseminates into lymphoid organs and delivers its heterologous antigen. The attenuated strain effectively induces a cellular immune response to the cancerous cells while lowering the systemic inflammatory response. Hence, a KBMA P. aeruginosa microsyringe is an efficient and safe tool for in vivo antigen delivery.

Integrin α(v)β(3) expression is upregulated during tumor growth and invasion in newly formed endothelial cells in tumor neovasculature and in some tumor cells. A tetrameric RGD‐based peptide, regioselectively addressable functionalized template‐(cyclo‐[RGDfK])4 (RAFT‐RGD), specifically targets integrin α(v)β(3) in vitro and in vivo. When labeled with indium‐111, the RAFT‐RGD is partially reabsorbed and trapped in the kidneys, limiting its use for further internal targeted radiotherapy and imaging investigations. We studied the effect of Gelofusine on RAFT‐RGD renal retention in tumor‐bearing mice. Mice were imaged using single photon emission computed tomography and optical imaging 1 and 24 h following tracer injection. Distribution of RAFT‐RGD was further investigated by tissue removal and direct counting of the tracer. Kidney sections were analyzed by confocal microscopy. Gelofusine significantly induced a >50% reduction of the renal reabsorption of (111) In‐DOTA‐RAFT‐RGD and A700‐RAFT‐RGD, without affecting tumor uptake. Injection of Gelofusine significantly reduced the renal retention of labeled RAFT‐RGD, while increasing the tumor over healthy tissue ratio. These results will lead to the development of future therapeutic approaches. (C ancer S ci 2012; 103: 1105–1110)