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Despite numerous molecular targeted therapies tested in glioblastoma (GBM), no significant progress in patient survival has been achieved in the last 20 years in the overall population of GBM patients except with TTfield setup associated with the standard of care chemoradiotherapy. Therapy resistance is associated with target expression heterogeneity and plasticity between tumors and in tumor niches. We focused on α5 integrin implicated in aggressive GBM in preclinical and clinical samples. To address the characteristics of α5 integrin heterogeneity we started with patient data indicating that elevated levels of its mRNA are related to hypoxia pathways. We turned on glioma stem cells which are considered at the apex of tumor formation and recurrence but also as they localize in hypoxic niches. We demonstrated that α5 integrin expression is stem cell line dependent and is modulated positively by hypoxia in vitro. Importantly, heterogeneity of expression is conserved in in vivo stem cell-derived mice xenografts. In hypoxic niches, HIF-2α is preferentially implicated in α5 integrin expression which confers migratory capacity to GBM stem cells. Hence combining HIF-2α and α5 integrin inhibitors resulted in proliferation and migration impairment of α5 integrin expressing cells. Stabilization of HIF-2α is however not sufficient to control integrin α5 expression. Our results show that AHR (aryl hydrocarbon receptor) expression is inversely related to HIF-2α and α5 integrin expressions suggesting a functional competition between the two transcription factors. Collectively, data confirm the high heterogeneity of a GBM therapeutic target, its induction in hypoxic niches by HIF-2α and suggest a new way to attack molecularly defined GBM stem cells.
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Radiolabeled peptides are valuable tools for diagnosis or therapies; they are often radiofluorinated using an indirect approach based on an F-18 prosthetic group. Herein, we are reporting our results on the F-18 radiolabeling of three peptides using two different methods based on click reactions. The first one used the well-known CuAAC reaction, and the second one is based on our recently reported hetero-Diels-Alder (HDA) using a dithioesters (thia-Diels-Alder) reaction. Both methods have been automated, and the 18F-peptides were obtained in similar yields and synthesis time (37-39% decay corrected yields by both methods in 120-140 min). However, to obtain similar yields, the CuAAC needs a large amount of copper along with many additives, while the HDA is a catalyst and metal-free reaction necessitating only an appropriate ratio of water/ethanol. The HDA can therefore be considered as a minimalist method offering easy access to fluorine-18 labeled peptides and making it a valuable additional tool for the indirect and site-specific labeling of peptides or biomolecules.
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Química Clic , Cobre , Reacción de Cicloadición , Radioisótopos de Flúor , Péptidos , Química Clic/métodos , Radioisótopos de Flúor/química , Péptidos/química , Cobre/química , Marcaje Isotópico/métodos , Automatización , Catálisis , Radiofármacos/química , Radiofármacos/síntesis químicaRESUMEN
Pathogens and pests constantly challenge food security and safety worldwide. The use of plant protection products to manage them raises concerns related to human health, the environment, and economic costs. Basic substances are active, non-toxic compounds that are not predominantly used as plant protection products but hold potential in crop protection. Basic substances' attention is rising due to their safety and cost-effectiveness. However, data on their protection levels in crop protection strategies are lacking. In this review, we critically analyzed the literature concerning the field application of known and potential basic substances for managing diseases and pests, investigating their efficacy and potential integration into plant protection programs. Case studies related to grapevine, potato, and fruit protection from pre- and post-harvest diseases and pests were considered. In specific cases, basic substances and chitosan in particular, could complement or even substitute plant protection products, either chemicals or biologicals, but their efficacy varied greatly according to various factors, including the origin of the substance, the crop, the pathogen or pest, and the timing and method of application. Therefore, a careful evaluation of the field application is needed to promote the successful use of basic substances in sustainable pest management strategies in specific contexts.
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BACKGROUND & AIMS: Despite recent approvals, the response to treatment and prognosis of patients with advanced hepatocellular carcinoma (HCC) remain poor. Claudin-1 (CLDN1) is a membrane protein that is expressed at tight junctions, but it can also be exposed non-junctionally, such as on the basolateral membrane of the human hepatocyte. While CLDN1 within tight junctions is well characterized, the role of non-junctional CLDN1 and its role as a therapeutic target in HCC remains unexplored. METHODS: Using humanized monoclonal antibodies (mAbs) specifically targeting the extracellular loop of human non-junctional CLDN1 and a large series of patient-derived cell-based and animal model systems we aimed to investigate the role of CLDN1 as a therapeutic target for HCC. RESULTS: Targeting non-junctional CLDN1 markedly suppressed tumor growth and invasion in cell line-based models of HCC and patient-derived 3D ex vivo models. Moreover, the robust effect on tumor growth was confirmed in vivo in a large series of cell line-derived xenograft and patient-derived xenograft mouse models. Mechanistic studies, including single-cell RNA sequencing of multicellular patient HCC tumorspheres, suggested that CLDN1 regulates tumor stemness, metabolism, oncogenic signaling and perturbs the tumor immune microenvironment. CONCLUSIONS: Our results provide the rationale for targeting CLDN1 in HCC and pave the way for the clinical development of CLDN1-specific mAbs for the treatment of advanced HCC. IMPACT AND IMPLICATIONS: Hepatocellular carcinoma (HCC) is associated with high mortality and unsatisfactory treatment options. Herein, we identified the cell surface protein Claudin-1 as a treatment target for advanced HCC. Monoclonal antibodies targeting Claudin-1 inhibit tumor growth in patient-derived ex vivo and in vivo models by modulating signaling, cell stemness and the tumor immune microenvironment. Given the differentiated mechanism of action, the identification of Claudin-1 as a novel therapeutic target for HCC provides an opportunity to break the plateau of limited treatment response. The results of this preclinical study pave the way for the clinical development of Claudin-1-specific antibodies for the treatment of advanced HCC. It is therefore of key impact for physicians, scientists and drug developers in the field of liver cancer and gastrointestinal oncology.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Animales , Ratones , Carcinoma Hepatocelular/genética , Claudina-1/genética , Neoplasias Hepáticas/genética , Carcinógenos , Microambiente Tumoral , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Línea Celular TumoralRESUMEN
With the entry into force of Regulation EC 1107/2009 and the important cut-off of a number of existing active substances from before 2011, which was processed from 342 in Annex I of Directive 91/414/EEC to 298, all these active substances are listed in Part A of Regulation EU 540/2011. Here, we have conducted a survey of all active substances since concerning their regulatory characteristics and their agricultural uses. Between 2011 and 2018, a global increase in active substances was observed with up to 502 approved, but since then an inexorable decline in the number active substances has occurred, despite numerous biocontrol agents (BCAs) being approved and only few chemicals. The newly approved active substances were then listed in Parts B, C, D and E, while renewed substances moved to Parts B to E. The impact of these changes was studied in relation to the availability of these substances and the corresponding global modifications in terms of employment, functions, uses, crops, and maximum residue limits. There has been a net loss of 53 active substances since 2018, notwithstanding 30 approvals, equates to a real loss of 95 active substances in the last 4 years and 118 since 2011. The main reduction of active substances is not only due to a falling-off of chemicals (95) but also a significant decay of BCA (19) impacting crop protection with an important reduction of the herbicides and a small increase of fungicides with an high replacement rate, with all crops being impacted, while the residue situation has greatly improved.
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Agricultura , Herbicidas , Unión Europea , Europa (Continente) , Productos AgrícolasRESUMEN
The HDA reaction of dithioesters was developed as a new click-reaction compatible with the indirect 18F-labelling of peptides. It involves dithioester-peptides and a radiofluorinated diene as a novel prosthetic group. The method was applied to a PSMA-ligand for the in vivo detection of LNCap tumors in xenografted mice.
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Péptidos , Animales , Catálisis , Reacción de Cicloadición , Ligandos , RatonesRESUMEN
Synthetic pesticides are widely used to protect crops from pathogens and pests, especially for fruits and vegetables, and this may lead to the presence of residues on fresh produce. Improving the sustainability of agriculture and, at the same time, reducing the adverse effects of synthetic pesticides on human health requires effective alternatives that improve the productivity while maintaining the food quality and safety. Moreover, retailers increasingly request fresh produce with the amounts of pesticides largely below the official maximum residue levels. Basic substances are relatively novel compounds that can be used in plant protection without neurotoxic or immune-toxic effects and are still poorly known by phytosanitary consultants (plant doctors), researchers, growers, consumers, and decision makers. The focus of this review is to provide updated information about 24 basic substances currently approved in the EU and to summarize in a single document their properties and instructions for users. Most of these substances have a fungicidal activity (calcium hydroxide, chitosan, chitosan hydrochloride, Equisetum arvense L., hydrogen peroxide, lecithins, cow milk, mustard seed powder, Salix spp., sunflower oil, sodium chloride, sodium hydrogen carbonate, Urtica spp., vinegar, and whey). Considering the increasing requests from consumers of fruits and vegetables for high quality with no or a reduced amount of pesticide residues, basic substances can complement and, at times, replace the application of synthetic pesticides with benefits for users and for consumers. Large-scale trials are important to design the best dosage and strategies for the application of basic substances against pathogens and pests in different growing environments and contexts.
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Quitosano , Residuos de Plaguicidas , Plaguicidas , Agricultura , Animales , Bovinos , Quitosano/análisis , Femenino , Contaminación de Alimentos/análisis , Frutas/química , Residuos de Plaguicidas/análisis , Plaguicidas/química , Verduras/químicaRESUMEN
PURPOSE: The main objective of the present study was to compare the 2-deoxy-2-[18F]fluoro-D-glucose ([18F]-FDG) and 3'-[18F]fluoro-3'-deoxythymidine ([18F]-FLT) PET imaging biomarkers for the longitudinal follow-up of small animal proton therapy studies in the context of hepatocellular carcinoma (HCC). PROCEDURES: SK-HEP-1 cells were injected into NMRI nude mice to mimic human HCC. The behavior of [18F]-FDG and [18F]-FLT tumor uptake was evaluated after proton therapy procedures. The proton single-fraction doses were 5, 10, and 20 Gy, with a dose rate of 10 Gy/min. The experimental protocol consisted of 8 groups of 10 mice, each group experiencing a particular dose/radiotracer condition. A reference PET exam was performed on each mouse the day before the irradiation procedure, followed by PET exams every 3 days up to 16 days after irradiation. RESULTS: [18F]-FDG uptake showed a linear dose-dependent increase in the first days after treatment (37%, p < 0.05), while [18F]-FLT uptake decreased in a dose-dependent manner (e.g., 21% for 5 Gy compared to 10 Gy, p = 1.1e-2). At the later time point, [18F]-FDG normalized activity showed an 85% decrease (p < 0.01) for both 10 and 20 Gy doses and no variation for 5 Gy. Conversely, a significant 61% (p = 0.002) increase was observed for [18F]-FLT normalized activity at 5 Gy and no variation for higher doses. CONCLUSION: We showed that the use of the [18F]-FDG and [18F]-FLT radiolabeled molecules can provide useful and complementary information for longitudinal follow-up of small animal proton therapy studies in the context of HCC. [18F]-FDG PET imaging enables a treatment monitoring several days/weeks postirradiation. On the other hand, [18F]-FLT could represent a good candidate to monitor the treatment few days postirradiation, in the context of hypo-fractioned and close irradiation planning. This opens new perspectives in terms of treatment efficacy verification depending on the irradiation scheme.
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Carcinoma Hepatocelular , Didesoxinucleósidos , Fluorodesoxiglucosa F18 , Neoplasias Hepáticas , Tomografía de Emisión de Positrones , Animales , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/terapia , Didesoxinucleósidos/química , Didesoxinucleósidos/farmacocinética , Modelos Animales de Enfermedad , Femenino , Fluorodesoxiglucosa F18/química , Fluorodesoxiglucosa F18/farmacocinética , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/terapia , Ratones , Ratones Desnudos , Terapia de ProtonesRESUMEN
Over-reliance on pesticides for pest control is inflicting serious damage to the environmental services that underpin agricultural productivity. The widespread use of systemic insecticides, neonicotinoids, and the phenylpyrazole fipronil in particular is assessed here in terms of their actual use in pest management, effects on crop yields, and the development of pest resistance to these compounds in many crops after two decades of usage. Resistance can only be overcome in the longterm by implementing methods that are not exclusively based on synthetic pesticides. A diverse range of pest management tactics is already available, all of which can achieve efficient pest control below the economic injury level while maintaining the productivity of the crops. A novel insurance method against crop failure is shown here as an example of alternative methods that can protect farmer's crops and their livelihoods without having to use insecticides. Finally, some concluding remarks about the need for a new framework for a truly sustainable agriculture that relies mainly on natural ecosystem services instead of chemicals are included; this reinforcing the previous WIA conclusions (van der Sluijs et al. Environ Sci Pollut Res 22:148-154, 2015).
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Insecticidas , Plaguicidas , Ecosistema , Neonicotinoides , Control de PlagasRESUMEN
Fluorescent probes are commonly used in studying G protein-coupled receptors in living cells; however their application to the whole animal receptor imaging is still challenging. To address this problem, we report the design and the synthesis of the first near-infrared emitting fluorogenic dimer with environment-sensitive folding. Due to the formation of non-fluorescent H-aggregates in an aqueous medium, the near-infrared fluorogenic dimer displays a strong turn-on response (up to 140-fold) in an apolar environment and exceptional brightness: 56% quantum yield and ≈444 000 M-1 cm-1 extinction coefficient. Grafted on a ligand of the oxytocin receptor, it allows the unprecedented background-free and target-specific imaging of the naturally expressed receptor in living mice.
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The use of biocontrol agents (BCAs) is growing across the world and in Europe in particular, where novel ways of farming are highly encouraged and implemented. However, although the social pressure is high to increase the number of BCAs in use within the EU, the European plant protection products (PPP) regulation (EC) N° 1107/2009 does not define clearly what BCAs are. Therefore, problems and drawbacks are observed throughout the whole authorisation process. Consequently, this situation impedes drastically the rapid implementation of botanical BCAs and their subsequent use in the field. Previous studies described in detail the fate of BCAs and the current administrative process that leads to their approval. Drawbacks are described for GMOs but surprisingly scarcely for pesticides. Therefore, the present study pinpoints the drawbacks of the approval process of botanical BCAs. To achieve this goal, a comparative study of 5 substances (4 of plant origin and 1 chemical) was performed. This study clearly reveals the present weaknesses and loopholes in the European PPP regulation process. The results of the present study may be useful to initiate and promote a major change in the evaluation and the regulation process of BCAs. This should allow designing a novel and innovative framework enabling the development of future plant protection products according to the sustainable use of pesticides, described in the corresponding (EC) Directive N° 128/2009 (SUD). This work targets farmers, policy makers, NGOs and scientists interested in issues related to this topic.
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Agricultura , Plaguicidas , Europa (Continente)RESUMEN
Synthetic pesticides are largely decried. A common attitude against the synthetic agrochemicals is to avoid, criticise or ban these substances. Along with chemical pesticides to defend crops from bioagressors are microorganisms, semiochemical and natural substances used as plant protection products including biocontrol agents (BCAs) and crop protection products in organic production. Nevertheless, a natural substance status does not confer or imply safety, security or absence of residues (in the context of plant protection). Although in this paper we do not consider the toxicological perspective of highly toxic chemicals with adverse effects on humans and non-target organisms sprayed on crops, we have applied ourselves to working on the safe use of synthetic agrochemicals. Thus, along with biopesticides (either BCA or others) allowed in organic farming, we show that some synthetic chemical pesticides may be used in safe manner. HIGHLIGHTS: ⢠Synthetic agrochemicals are widely criticised. ⢠Some pesticide usages are not sprayed on crops. ⢠Some biocontrol agents are of synthetic origin.
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Agroquímicos/análisis , Agentes de Control Biológico/análisis , Protección de Cultivos/métodos , Productos Agrícolas , Agroquímicos/farmacología , Agentes de Control Biológico/farmacología , Protección de Cultivos/economía , Protección de Cultivos/legislación & jurisprudencia , Productos Agrícolas/química , Productos Agrícolas/efectos de los fármacos , Unión Europea , Humanos , Residuos de Plaguicidas/análisisRESUMEN
BACKGROUND: The use of biocontrol agents (BCA) is growing strongly with a market of 1.9 billion worldwide and 542 million in Europe, and an estimated annual growth of between 15% and 20%. Biocontrol substances use natural mechanisms as part of integrated pest management. With the exception of macro-organisms, substances or products comprising microorganisms, semiochemicals and natural substances depend on plant protection Regulation (EC) No. 1107/2009. RESULTS: When this regulation came into force, a number of BCA had already been approved. The total number of BCA rose during the period 2011-2018 to â¼ 60 substances in line with global growth in approved substances. This growth was not smooth or equal between biocontrol categories; the microorganisms category increased the most, with a doubling of the number of approved substances in use, followed by natural substances and semiochemicals. CONCLUSION: This positive development has been influenced by many factors such as scientific advances and environmental characteristics. However, some obstacles remain that limit the development of BCA (market size, variability in effectiveness, etc.). Regulatory measures could be a key to enhancing the development of biocontrol registrations. © 2018 Society of Chemical Industry.
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Agentes de Control Biológico/análisis , Unión Europea , Control Biológico de Vectores/legislación & jurisprudenciaRESUMEN
BACKGROUND: Plasmopara viticola control in organic viticulture requires copper-based fungicides with harmful effects on health and the environment. Plant extracts represent a biorational eco-friendly alternative to copper. The aim of this study was to evaluate the potential of stilbenoid-rich grape cane extract (GCE) against downy mildew on three cultivars over 3 years following natural downy mildew infection. RESULTS: Over all field trials, GCE treatments showed an average reduction in disease incidence of -35% and -38% on leaves and clusters, respectively. The average reduction in disease severity was -35% and -43% on leaves and clusters, respectively. Under artificial downy mildew infection, GCE efficacy corresponded to 1 g L-1 of copper. Neither phytotoxicity nor adverse effects on auxiliary fauna were observed after treatment with GCE. CONCLUSION: Because few or no biocontrol agents are active alone against P. viticola, GCE is a promising alternative to copper-based fungicides. Grape canes, an abundant by-product of viticulture, have great potential for valorization as a biocontrol agent for sustainable viticulture. © 2018 Society of Chemical Industry.
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Oomicetos/fisiología , Enfermedades de las Plantas/microbiología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Estilbenos/química , Vitis/química , Vitis/microbiología , Oomicetos/efectos de los fármacosRESUMEN
INTRODUCTION: Platelets play a major role in thrombo-embolic diseases, notably by forming a thrombus that can ultimately occlude a vessel. This may provoke ischemic pathologies such as myocardial infarction, stroke or peripheral artery diseases, which represent the major causes of death worldwide. The aim of this study was to evaluate the specificity of radiolabeled Rat-Anti-Mouse antibody (RAM.1). METHODS: We describe a method to detect platelets by using a RAM.1 coupled with the chelating agent hydrazinonicotinic acid (HYNIC) conjugated to 99mTc, for Single Photon Emission Computed Tomography (SPECT). To induce platelet accumulation at a site of interest, we used a mouse model of FeCl3 induced injury of the carotid artery. 90â¯min after i.v. injection of [99mTc][Tc(HYNIC)-RAM.1], biodistribution of the radiolabeled RAM.1 was assessed, SPECT imaging and histological analysis were performed on the mice that underwent FeCl3-induced vessel damage. RESULTS: We demonstrated a quick and strong affinity of the radiolabeled RAM.1 for the platelet thrombus. Results clearly demonstrated the ability of this radioimmunoconjugate for detecting thrombi from 10â¯min post injection with an exceptional thrombi uptake. Using FeCl3, the median ratio between the thrombus and the background was 12.4 (range 9.3-42.3) as compared to 1.0 (range: 0.86-2.7) pâ¯<â¯0.05 when using 0.9% NaCl. CONCLUSION: Thanks to the high sensitivity of SPECT, we provided evidence that [99mTc][Tc(HYNIC)-RAM.1] represents a powerful tool to detect localized platelet thrombi which could potentially be used in humans. Because of the relative low cost and high sensitivity, these results encourage further study like the detection of non-induced thrombus and further developments toward clinical application. This is further supported by the fact that RAM.1 recognizes human platelets.
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Anticuerpos Monoclonales/química , Compuestos de Organotecnecio/química , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único/métodos , Trombosis/diagnóstico por imagen , Animales , Anticuerpos Monoclonales/farmacocinética , Arterias Carótidas/diagnóstico por imagen , Marcaje Isotópico , Ratones , Distribución TisularRESUMEN
Piperonyl butoxide is a semi-synthetic synergist for natural pyrethrum and synthetic pyrethroid insecticides in phytochemicals and biocides. As such it is used in large quantities for crop treatments, stored grain protection, disinfestation of grain storage facilities and indoor uses. Piperonyl butoxide is consequently a regular contaminant in stored grains, and subsequently in corresponding cereal food products and meat via feed uses. Therefore it is regularly monitored and its MRL is ongoing a reassessment. It is also considered as a possible human carcinogen and a suspected endocrine disruptor. For all these reasons and considerations most of the countries have already banned its use in Organic Farming as France in 2017. Thus, ecological substitution of with biorational and sustainable solutions is required. Vegetable oils have been described as exhibiting similar potency and synergistic effects. We have reviewed the literature and have proceeded to ecotoxicological efficacy tests in order to determine the best and most durable substitution candidates. Sesame and rape seed oil were determined to be the most efficient.
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Insecticidas/química , Sinergistas de Plaguicidas/química , Butóxido de Piperonilo/química , Aceites de Plantas/química , Piretrinas/química , Animales , Chrysanthemum cinerariifolium , Francia , Humanos , Insectos/efectos de los fármacos , Insecticidas/síntesis química , Insecticidas/farmacología , Piretrinas/síntesis química , Piretrinas/farmacologíaRESUMEN
INTRODUCTION: Herein we have evaluated the uptake of O-(2-18F-fluoroethyl)-l-tyrosine (18F-FET) in insulinoma in comparison with those of 6-18F-fluoro-3,4-dihydroxy-l-phenylalanine (18F-FDOPA) providing first data from both murine xenograft model and one patient with proved endogenous hyperinsulinemic hypoglycemia. METHODS: Dynamic 18F-FET and carbidopa-assisted 18F-FDOPA PET were performed on tumor-bearing nude mice after subcutaneous injection of RIN-m5F murine beta cells and on a 30-year-old man with type-1 multiple endocrine neoplasia and hyperinsulinemic hypoglycemia defined by a positive fasting test. RESULTS: Seven and three nude mice bearing a RIN-m5F insulinoma xenograft were respectively studied by 18F-FET and 18F-FDOPA µPET. Insulinoma xenograft was detected in all the imaged animals. Xenograft was characterized by an early but moderate increase of 18F-FET uptake followed by a slight decline of uptake intensity during the 20 min dynamic acquisition. Tumoral radiotracer peak intensity and the highest tumor-to-background contrast were reached about 5 minutes after 18F-FET iv. injection (mean SUV: 1.21 ± 0.10). The biodistribution of 18F-FET and 18F-FDOPA and their dynamic tumoral uptake profile and intensity were similar. In the examined patient, 18F-FDOPA and 18F-FET PET/CT showed one concordant focal area of well-defined increased uptake in the pancreatic tail corresponding to 11 mm histologically proved insulinoma. The SUVmax tumor to liver ratio was 1.5, 1.1 for 18F-FDOPA, 1.1, 1 for 18F-FET at early (0-5 min post injection) and delayed (5-20 min post injection) PET/CT acquisition, respectively. Despite the relatively low tumoral uptake intensity, insulinoma was clearly identified due to the low background in the pancreas. At the contrary, no 18F-FDOPA or 18F-FET tumoral uptake was revealed on whole-body PET/CT images performed about 30 min after radiotracer administration. Note of worth, the dynamic uptake pattern of 18F-FET and 18F-FDOPA were similar between human insulinoma and mice xenograft tumor. CONCLUSION: 18F-FET PET compared equally to 18F-FDOPA PET in a preclinical RIN-m5F murine model of insulinoma and in one patient with insulinoma-related hypoglycemia. However, in both cases, the tumoral uptake intensity was moderate and the tumor was only visible until 20 min after radiotracer injection. Hence, caution should be taken before asserting the translational relevance of our results in the clinical practices. However, the structural analogies between 18F-FET and 18F-FDOPA as well as the limited pancreatic uptake of 18F-FET in human, encourage evaluating 18F-FET as diagnostic radiotracer for insulinoma detection in further prospective studies involving large cohorts of patients.
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Transformación Celular Neoplásica , Insulinoma/metabolismo , Insulinoma/patología , Tirosina/análogos & derivados , Adulto , Animales , Transporte Biológico , Línea Celular Tumoral , Femenino , Humanos , Insulinoma/diagnóstico por imagen , Masculino , Ratones , Ratones Desnudos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Tirosina/metabolismoRESUMEN
Patient premedication with carbidopa seems to improve the accuracy of 6-18F-fluoro-3,4-dihydroxy-l-phenylalanine (18F-FDOPA) PET for insulinoma diagnosis. However, the risk of PET false-negative results in the presence of carbidopa is a concern. Consequently, we aimed to evaluate the effect of carbidopa on 18F-FDOPA uptake in insulinoma ß-cells and an insulinoma xenograft model in mice. METHODS: 18F-FDOPA in vitro accumulation was assessed in the murine ß-cell line RIN-m5F. In vivo small-animal PET experiments were performed on tumor-bearing nude mice after subcutaneous injection of RIN-m5F cells. Experiments were conducted with and without carbidopa pretreatment. RESULTS: Incubation of RIN-m5F cells with 80 µM carbidopa did not significantly affect the cellular accumulation of 18F-FDOPA. Tumor xenografts were clearly detectable by small-animal PET in all cases. Insulinoma xenografts in carbidopa-treated mice showed significantly higher 18F-FDOPA uptake than those in nontreated mice. Regardless of carbidopa premedication, the xenografts were characterized by an early increase in 18F-FDOPA uptake and then a progressive reduction over time. CONCLUSION: Carbidopa did not influence in vitro 18F-FDOPA accumulation in RIN-m5F cells but improved insulinoma imaging in vivo. Our findings increase current knowledge about the 18F-FDOPA uptake profile of RIN-m5F cells and a related xenograft model. To our knowledge, the present work represents the first preclinical research specifically focused on insulinomas, with potential translational implications.
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Carbidopa/administración & dosificación , Dihidroxifenilalanina/análogos & derivados , Insulinoma/metabolismo , Neoplasias Pancreáticas/diagnóstico por imagen , Neoplasias Pancreáticas/metabolismo , Tomografía de Emisión de Positrones/métodos , Animales , Línea Celular Tumoral , Dihidroxifenilalanina/farmacocinética , Femenino , Aumento de la Imagen/métodos , Insulinoma/diagnóstico por imagen , Tasa de Depuración Metabólica/efectos de los fármacos , Ratones Desnudos , Especificidad de Órganos/efectos de los fármacos , Radiofármacos/farmacocinética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Distribución Tisular/efectos de los fármacosRESUMEN
INTRODUCTION: Since 1991 until now, many radiosyntheses of [(18)F]FLT have been published. Most of them suffer from side reactions and/or difficult purification related to the large amount of precursor necessary for the labeling step. A fully automated synthesis using only commercial and unmodified materials with a reduced amount of precursor would be desirable. METHODS: We first explored the possibility to elute efficiently [(18)F]fluorine from commercial and unmodified cartridges with various amount of base. Based on these results, 10mg and 5mg of precursors were used for the fluorination step. The best conditions were transposed in an automated process for a one pot two steps synthesis of labeled FLT. RESULTS: Using commercial and non-treated carbonate form of QMA cartridges, we were able to elute quantitatively the [(18)F]fluorine with a very low amount of base (0.59mg) and, with only 5mg of precursor, to perform an efficient fluorination reaction with up to 94% incorporation of [(18)F]fluorine. The synthesis was fully automated and radiochemical yields of 54% (decay corrected) were obtained within a synthesis time of 52minutes. CONCLUSION: We demonstrate that a fully automated and efficient radiosynthesis of [(18)F]FLT is feasible with only 5mg of precursor. Compare to the present state of the art, our method provides high yields of pure [(18)F]FLT and is broadly adaptable to other synthesis automates.
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Didesoxinucleósidos/química , Didesoxinucleósidos/síntesis química , Radioquímica/métodos , Automatización , Técnicas de Química Sintética , Control de CalidadRESUMEN
Plant extracts and byproducts furnish various alternative products for crop protection and are traditionally used by farmers. However, the cost and timeframe for their registration as active substances are prohibitive for small companies and farmers' associations with the new Plant Protection Products (PPP) Regulation (EC) No. 1107/2009. However, there is now a possibility of registering light compounds as 'basic substances', a new category described in Article 23 and in 'Whereas/Recital 18'. We developed a regulatory expertise on the approval of such products within the framework of the PPP regulation. A Draft Assessment Report in one volume was established, later transformed by EC Directorate into a Basic Substance Application Template, and subsequently used by the EC as a matrix for the corresponding Guidelines for applicants (SANCO 10363/2012 rev. 9). Here we provide further tools, consisting of methodological, linguistic and strategic recommendations in order to constitute a Basic Substance Application (BSA) and proceed to its registration. While the use of alternative agents for crop protection is increasing both in organic and conventional agriculture, these usages are still considered as 'minor uses'. Our approach and tools are valuable to non-PPP specialised applicants for simplifying and facilitating their submission of the BSA.