Target fishing reveals PfPYK-1 and PfRab6 as potential targets of an antiplasmodial 4-anilino-2-trichloromethylquinazoline hit compound.

We present investigations about the mechanism of action of a previously reported 4-anilino-2-trichloromethylquinazoline antiplasmodial hit-compound (Hit A), which did not share a common mechanism of action with established commercial antimalarials and presented a stage-specific effect on the erythrocytic cycle of P. falciparum at 8 < t < 16 h. The target of Hit A was searched by immobilising the molecule on a solid support via a linker and performing affinity chromatography on a plasmodial lysate. Several anchoring positions of the linker (6,7 and 3') and PEG-type linkers were assessed, to obtain a linked-hit molecule displaying in vitro antiplasmodial activity similar to that of unmodified Hit A. This allowed us to identify the PfPYK-1 kinase and the PfRab6 GTP-ase as potential targets of Hit A.

Molecular basis of agonist docking in a human GPR103 homology model by site-directed mutagenesis and structure-activity relationship studies.

BACKGROUND AND PURPOSE: The neuropeptide 26RFa and its cognate receptor GPR103 are involved in the control of food intake and bone mineralization. Here, we have tested, experimentally, the predicted ligand-receptor interactions by site-directed mutagenesis of GPR103 and designed point-substituted 26RFa analogues. EXPERIMENTAL APPROACH: Using the X-ray structure of the ß2 -adrenoceptor, a 3-D molecular model of GPR103 has been built. The bioactive C-terminal octapeptide 26RFa(19-26) , KGGFSFRF-NH2 , was docked in this GPR103 model and the ligand-receptor complex was submitted to energy minimization. KEY RESULTS: In the most stable complex, the Phe-Arg-Phe-NH2 part was oriented inside the receptor cavity, whereas the N-terminal Lys residue remained outside. A strong intermolecular interaction was predicted between the Arg(25) residue of 26RFa and the Gln(125) residue located in the third transmembrane helix of GPR103. To confirm this interaction experimentally, we tested the ability of 26RFa and Arg-modified 26RFa analogues to activate the wild-type and the Q125A mutant receptors transiently expressed in CHO cells. 26RFa (10(-6) M) enhanced [Ca(2+) ]i in wild-type GPR103-transfected cells, but failed to increase [Ca(2+) ]i in Q125A mutant receptor-expressing cells. Moreover, asymmetric dimethylation of the side chain of arginine led to a 26RFa analogue, [ADMA(25) ]26RFa(20-26) , that was unable to activate the wild-type GPR103, but antagonized 26RFa-evoked [Ca(2+) ]i increase. CONCLUSION AND IMPLICATIONS: Altogether, these data provide strong evidence for a functional interaction between the Arg(25) residue of 26RFa and the Gln(125) residue of GPR103 upon ligand-receptor activation, which can be exploited for the rational design of potent GPR103 agonists and antagonists.

Rapid and soft formulation of folate-functionalized nanoparticles for the targeted delivery of tripentone in ovarian carcinoma.

We report the development of folate-functionalized nanoparticles able to target folate receptors, and to deliver a poorly water soluble cytotoxic agent, a tripentone, in ovarian carcinoma. The stability under incubation of lipid nanoparticles formulated by a low-energy phase inversion temperature method was investigated. Thanks to the presence of Labrasol(®), a macrogolglyceride into the composition of the nanocarriers, the conjugation of different quantities of a folate derivate (folic acid-polyethylene glycol2000-distearylphosphatidylethanolamine) to nanoparticles was possible by a rapid, soft, very simple post-insertion process. As determined by dynamic light scattering, nanoparticles present a monodisperse diameter of about 100 nm, a spherical shape as attested by transmission electron micrographs, a weakly negative surface zeta potential, and are able to encapsulate the tripentone MR22388. The presence of folate receptors on SKOV3 human ovarian cancer cells was identified by fluorescent immunocytochemistry. Cellular uptake studies assessed by flow cytometry indicated that these nanoparticles reached the SKOV3 cells rapidly, and were internalized by a folate-receptor mediated endocytosis pathway. Moreover, nanoparticles allowed the rapid delivery of the antitumor agent tripentone into cells as shown in vitro by real-time cellular activity assay. Such folate-lipid nanoparticles are a potential carrier for targeted delivery of poorly water soluble compounds into ovarian carcinoma.

Targeting the BH3 domain of Bcl-2 family proteins. A brief history from natural products to foldamers as promising cancer therapeutic avenues.

For many years the spotlight in drug discovery has been on a relatively small number of validated therapeutic target classes, such as G-protein coupled receptors and enzymes such as protein kinases, with well characterized enzymatic and cellular activities. However, with recent progress in genomics and proteomics, protein-protein interactions (PPIs) provide new way of finding novel bioactive molecules acting on their interfaces. This review addresses the current case studies and state of the art in the development of small chemical modulators controlling interactions of proteins that have pathological implications in various human diseases and in particular in cancer. The attention is focused on Bcl-2 family protein modulators ranging from natural products to synthetic ones with particular interest in foldamers as BH3 alpha helix mimetics.

[Breast cancer on a scar of excision of ectopic breast tissue: a case report]. / Cancer du sein sur la cicatrice d'exérèse d'un tissu mammaire ectopique: à propos d'un cas.

The cancerization of supernumerary breast is uncommon. So when this situation occurs, the diagnosis is often late. Cancers of ectopic breast tissue have been reported in the international literature, but to our knowledge, no cancer after excision of accessory breast gland has been published. This article describes a case of ectopic breast tissue cancer in axillary situation occurring several years after excision and details its specific diagnostic, therapeutic and prognosis.

Partial least squares analysis and mixture design for the study of the influence of composition variables on lipidic nanoparticle characteristics.

Lipidic nanoparticles (NP), formulated from a phase inversion temperature process, have been studied with chemometric techniques to emphasize the influence of the four major components (Solutol®, Labrasol®, Labrafac®, water) on their average diameter and their distribution in size. Typically, these NP present a monodisperse size lower than 200 nm, as determined by dynamic light scattering measurements. From the application of the partial least squares (PLS) regression technique to the experimental data collected during definition of the feasibility zone, it was established that NP present a core-shell structure where Labrasol® is well encapsulated and contributes to the structuring of the NP. Even if this solubility enhancer is regarded as a pure surfactant in the literature, it appears that the oil moieties of this macrogolglyceride mixture significantly influence its properties. Furthermore, results have shown that PLS technique can be also used for predictions of sizes for given relative proportions of components and it was established that from a mixture design, the quantitative mixture composition to use in order to reach a targeted size and a targeted polydispersity index (PDI) can be easily predicted. Hence, statistical models can be a useful tool to control and optimize the characteristics in size of NP.

Influence of the introduction of a solubility enhancer on the formulation of lipidic nanoparticles with improved drug loading rates.

The objective of the present paper is to develop lipidic nanoparticles (NP) able to encapsulate drugs presenting limited solubility in both water and lipids, with high loading rates, and without using organic solvents. In this goal, a solubility enhancer, a macrogolglyceride (Labrasol), was incorporated in a formulation process based on a low-energy phase inversion temperature method. From electrical conductivity through the temperature scans, it appears that presence of Labrasol does not prevent the phase inversion, and it takes part in the microemulsion structuring, probably of bicontinuous type. After screening pseudo-ternary diagrams, the feasibility of NP was established. From results of a partial least square analysis, it appears that these NP present a core-shell structure where Labrasol is well encapsulated and contributes to the formation of the oily liquid core of the NP. The diameter of the NP, assessed by dynamic light scattering, remains kinetically stable. These NP, smaller than 200 nm, spherical in shape as attested by cryo-transmission electron micrographs, are able to encapsulate a tripentone, a new anticancer agent, with drug loading rates up to 6.5% (w/w). So highly drug-loaded lipidic nanocarriers were developed without using the slightest organic solvent trace, and making it easily possible dose adjustment.

[Thrombophlebitis of the right ovarian vein with thrombosis of the inferior vena cava in the post-partum]. / Thrombose de la veine ovarienne droite remontant jusqu'à la veine cave inférieure dans le post-partum.

A 31-year-old woman presented, in post-partum day two, an abdominal pain associated with fever. Appendicitis was suspected on clinical and radiological elements, and a laparoscopy carried out. This found a normal appendix but a right ovarian vein thrombophlebitis. A second injected scan confirmed the diagnosis, the right renal vein and the inferior vena cava being affected. We started an anticoagulation treatment associated with a large antibiotherapy. The patient was transferred to the intensive care unit to prevent the risk of pulmonary embolism.

Synthesis and biological evaluation of novel pyrrolopyrrolizinones as anticancer agents.

We herein describe the synthesis of novel 3-(het)aryl-pyrrolo[2,3-b]pyrrolizin-8(1H)-ones starting from commercial (het)aryl-acetonitriles. A more convergent route was also described through the first synthesis of ethyl 3-amino-4-bromo-1H-pyrrole-2-carboxylate 17. The antiproliferative activities of these compounds were tested toward various cell lines and one of them 10k shows interesting cytotoxic properties, although it was less potent than our lead compound in thiophene series 1k.

Formulation of sustained release nanoparticles loaded with a tripentone, a new anticancer agent.

The purpose of the present work is to develop nanoparticles of a new antitubulin agent of the family of tripentones by means of a phase inversion process. Dynamic light scattering, transmission electron microscopy and zeta-potential measurements were used to characterize tripentone loaded nanoparticles. From interfacial tension measurements and from the study of the rheological interfacial properties of the tripentone at the Labrafac-Solutol interface, the fraction of tripentone initially present in Labrafac would stay in the oily core of nanocapsules. Moreover, the interpenetration of some tripentone molecules within the surfactant units helps to the stabilization of the formulated nanoparticles. The encapsulation efficiency was determined by high performance liquid chromatography (HPLC) and was found to be above 95%. In vitro release studies were carried out in blank nanoparticles containing phosphate buffer, pH 7.4, at 37 degrees C. The drug release kinetics was measured by HPLC. Antiproliferative activity studies on L1210 cells showed that the cytotoxic activity of tripentone was totally recovered after encapsulation of the antitubulin agent in lipid nanoparticles. This study shows that lipid nanocapsules could be a promising and effective carrier for tripentone delivery in the treatment of cancers.

New risk assessment approach for systemic insecticides: the case of honey bees and imidacloprid (Gaucho).

The procedure to assess the risk posed by systemic insecticides to honey bees follows the European Directives and depends on the determination of the Hazard Quotient (HQ), though this parameter is not adapted to these molecules. This paper describes a new approach to assess more specifically the risk posed by systemic insecticides to honey bees with the example of imidacloprid (Gaucho). This approach is based on the new and existing chemical substances Directive in which levels of exposure (PEC, Predicted Exposure Concentration) and toxicity (PNEC, Predicted No Effect Concentration) are compared. PECs are determined for different categories of honey bees in relation to the amounts of contaminated pollen and nectar they might consume. PNECs are calculated from data on acute, chronic, and sublethal toxicities of imidacloprid to honey bees, to which selected assessment factors are applied. Results highlight a risk for all categories of honey bees, in particular for hive bees. These data are discussed in the light of field observations made on honey bee mortalities and disappearances. New perspectives are given to better determine the risk posed by systemic insecticides to honey bees.

[Amniotic fluid embolism: two case reports]. / Embolie de liquide amniotique: à propos de deux cas.

We report two cases of amniotic fluid embolism, confirmed by histological examination. Both patients had an immediate post-partum haemorrhage that required an haemostatic hysterectomy. A typical symptomatology of amniotic fluid embolism revelated the first case. The patient survived without any sequelae. In the second case, amniotic fluid embolism occurred immediately after the delivery. The patient developed an acute respiratory distress with a shock syndrome. Despite haemostatic hysterectomy and resuscitative efforts, she died 6 days later.

The maximum common substructure as a molecular depiction in a supervised classification context: experiments in quantitative structure/biodegradability relationships.

The maximum common structure between two molecules (MCS) induces a similarity that enables one to group compounds sharing the same pattern. This text relates a study based on such a structural depiction in a context of quantitative structure/biodegradability relationships (QSBR). The similarity indices are based exclusively on the MCS. First, the results of statistical tests prove that these indices significantly group compounds of similar activity together. These first conclusions enable the elaboration of classification models using those structural similarities. In a second part, a population of classifiers relying on the maximum common structure and the k-nearest-neighbor algorithm is explored. Finally, a thorough examination of the best models is conducted.

Synthesis and preliminary behavioural evaluation in mice of new 3-aryl-3-pyrrol-1-ylpropanamides, analogues of FGIN-1-27 and FGIN-1-43.

The 2-aryl-3-indoleacetamides FGIN-1-27 and FGIN-1-43 have already been characterized in-vitro as potent and specific ligands for the mitochondrial DBI receptor. This affinity was associated with psychotropic properties in several rodent behavioural tasks (in particular anxiolytic action) via enhancement of GABA transmission through neurosteroid production. The synthesis of new 3-aryl-3-pyrrol-1-ylpropanamides 1a-i, analogues of FGIN-1-27 and FGIN-1-43, is described in four steps starting from the corresponding arylaldehydes. Preliminary evaluation of these compounds in behavioural studies (spontaneous locomotor activity and anxiolytic activity) in mice was also undertaken.

Solid phase synthesis of sulphonamides: novel ligands of 5-HT6 receptors.

Using solid phase synthesis techniques, we have rapidly obtained a series of eight aryl sulphonamides derived from putrescine. These conjugates with various aryl groups were evaluated for their affinity towards 5-HT6 receptors in man. This evaluation revealed the interest of two compounds which present the same activity level, in the submicromolar range, as two reference derivatives. The most potent will be considered as a new lead for further investigations.

Design, synthesis and antiproliferative activity of tripentones: a new series of antitubulin agents.

Structure-activity relationship studies of a new series of tripentones (thieno[2,3-b]pyrrolizin-8-ones), led us to prepare several derivatives with antiproliferative activities. The most promising 3-(3-hydroxy-4-methoxyphenyl)thieno[2,3-b]pyrrolizin-8-one 20 (leukemia L1210, IC(50)=15 nM) was shown to be a potent inhibitor of tubulin polymerization.

Prediction of the Daphnia acute toxicity from heterogeneous data.

Two descriptors (log(P(ow)), 'hardness') were selected to predict the Daphnia acute toxicity of a training set of heterogeneous chemical compounds. The data were extracted from 523 notification files about new chemicals stored at the French Department of Environment. The selection of the descriptors was carried out using a statistical method coupling ordinary least square (OLS) regression and genetic algorithm (GA). The validity limits for the final equation are discussed by comparing the actual and predicted activities of several compounds. The study points out the interest of the 'hardness' parameter for quantitative structure-activity relationships (QSAR) with a heterogeneous data set.

Association of two 3D QSAR analyses. application to the study of partial agonist serotonin-3 ligands.

CATALYST and COMFA, two software packages for 3D QSAR studies, were associated to correlate the three-dimensional structures of 75 serotonin 5-HT3 ligands to their biological affinities. The conformational analysis and the influence of chemical function-based alignments (the basis of this association) on final results are discussed in this publication. These two analyses allow for precisely quantitating the weights of significant chemical groups or functions on the biological affinities.

Inhibition of neuronal nitric oxide synthase by 7-methoxyindazole and related substituted indazoles.

The synthesis and pharmacological evaluation of methoxyindazoles as new inhibitors of neuronal nitric oxide synthase are presented. The 7-methoxyindazole, although less potent than 7-NI, is the most active compound of the series in an in vitro enzymatic assay of neuronal nitric oxide synthase activity. This result shows that the nitro-substitution is not indispensable to the biological activity of the indazole ring. 7-Methoxyindazole possesses in vivo NOS inhibitory as well and related antinociceptive properties.

First tricyclic oximino derivatives as 5-HT3 ligands.

The design and synthesis of a new type of 5-HT3 ligand with subnanomolar affinity are described. The O-dialkylaminoethyloximinothienopyrrolizine structure was deduced from molecular modeling studies by replacement of an amidine moiety by an oximino one.