Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 13 de 13
Filtrer
Plus de filtres











Base de données
Gamme d'année
1.
Life Sci ; 238: 116979, 2019 Dec 01.
Article de Anglais | MEDLINE | ID: mdl-31647947

RÉSUMÉ

AIMS: Alzheimer's disease (AD) is closely related to abnormal glucose metabolism in the central nervous system. Progesterone has been shown to have obvious neuroprotective effects in the pathogenesis of AD, but the specific mechanism has not been fully elucidated. Therefore, the purpose of this study was to investigate the effect of progesterone on the glucose metabolism of neurons in amyloid precursor protein (APP)/presenilin 1 (PS1) mice and Aß-induced AD cell model. MATERIALS AND METHODS: APP/PS1 mice were treated with 40 mg/kg progesterone for 40 days and primary cultured cortical neurons were treated with 1 µM progesterone for 48 h.Then behavior tests,2-NBDG glucose uptake tests and the protein levels of glucose transporter 3 (GLUT3), GLUT4, cAMP-response element binding protein (CREB) and proliferator-activated receptor γ (PPARγ) were examined. KEY FINDINGS: Progesterone increased the expression levels of GLUT3 and GLUT4 in the cortex of APP/PS1 mice, accompanied by an improvement in learning and memory. Progesterone increased the levels of CREB and PPARγ in the cerebral cortex of APP/PS1 mice. In vitro, progesterone increased glucose uptake in primary cultured cortical neurons, this effect was blocked by the progesterone receptor membrane component 1 (PGRMC1)-specific blocker AG205 but not by the progesterone receptor (PR)-specific blocker RU486. Meanwhile, progesterone increased the expression of GLUT3, GLUT4, CREB and PPARγ, and AG205 blocked this effect. SIGNIFICANCE: These results confirm that progesterone significantly improves the glucose metabolism of neurons.One of the mechanisms of this effect is that progesterone upregulates protein expression of GLUT3 and GLUT4 through pathways PGRMC1/CREB/GLUT3 and PGRMC1/PPARγ/GLUT4.


Sujet(s)
Maladie d'Alzheimer/traitement médicamenteux , Précurseur de la protéine bêta-amyloïde/physiologie , Modèles animaux de maladie humaine , Glucose/métabolisme , Neurones/effets des médicaments et des substances chimiques , Préséniline-1/physiologie , Progestérone/pharmacologie , Maladie d'Alzheimer/étiologie , Maladie d'Alzheimer/anatomopathologie , Peptides bêta-amyloïdes/pharmacologie , Animaux , Humains , Mâle , Souris , Souris transgéniques , Neurones/métabolisme , Neurones/anatomopathologie , Progestines/pharmacologie , Rats , Rat Sprague-Dawley
2.
J Pharmacol Sci ; 138(2): 89-95, 2018 Oct.
Article de Anglais | MEDLINE | ID: mdl-30340922

RÉSUMÉ

Tumor-associated macrophages (TAMs) has been regarded as the most prominent component in tumor microenvironment. The correlation between TAM density and poor prognosis in Hepatocellular carcinoma (HCC) patients suggests a supportive role for TAMs in tumor progression. Here we employed a co-culture system to interrogate the molecular link between Yes-Associated Protein (YAP) and TAMs chemotaxis in HCC cells. We found that YAP activation was critical for the recruitment of TAMs towards HCC cells. Furthermore, cytokine array and quantitative RT-PCR analyses showed that IL-6 secreted by YAP-activated HCC cells might induce the TAMs recruitment. Interrupting YAP function by statins, the inhibitors of hydroxymethylglutaryl-CoA reductase, could robustly suppress the chemotaxis of TAMs. Together with our findings that the expression levels ofIL-6inhumanHCC tumors were highly correlated with the prognosis of HCC patients, the current study highlight the possibility of improving HCC treatment by targeting YAP-IL-6 mediated TAMs recruitment.


Sujet(s)
Protéines adaptatrices de la transduction du signal/physiologie , Carcinome hépatocellulaire/anatomopathologie , Interleukine-6/métabolisme , Tumeurs du foie/anatomopathologie , Macrophages/anatomopathologie , Macrophages/physiologie , Phosphoprotéines/physiologie , Carcinome hépatocellulaire/métabolisme , Carcinome hépatocellulaire/thérapie , Lignée cellulaire , Chimiotaxie/effets des médicaments et des substances chimiques , Évolution de la maladie , Cellules HepG2 , Humains , Inhibiteurs de l'hydroxyméthylglutaryl-CoA réductase/pharmacologie , Tumeurs du foie/métabolisme , Tumeurs du foie/thérapie , Thérapie moléculaire ciblée , Pronostic , Facteurs de transcription , Microenvironnement tumoral , Protéines de signalisation YAP
3.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 44(5): 493-9, 2015 09.
Article de Chinois | MEDLINE | ID: mdl-26713522

RÉSUMÉ

OBJECTIVE: To determine the effect of the combination of lapatinib with chlorogenic acid on metastasis of breast cancer in mouse model. METHODS: The classical macrophage M2 polarization model induced by interlukin13in vitro was adopted in the study. Flow cytometric analysis was performed to detect the expression of M2 marker CD206. The transcription of M2-associated genes was measured by RT-PCR. HE staining was used to analyze the metastatic nodes of breast cancer in lungs of MMTV-PyVT mice. Immunostaining analysis was used to detect the expression of related proteins in breast cancer. RESULTS: The combination of lapatinib and chlorogenic acid inhibited the expression of CD206 induced by IL-13[(42.17%±2.59%) vs (61.15%±7.58%), P<0.05]. The combination more markedly suppressed expression of M2-associated gene Ym1 than lapatinib alone[(0.9±0.1) vs (1.8±0.0), P<0.05]. The combination of lapatinib and chlorogenic acid significantly reduced metastatic nodes in lung[P<0.05], and also significantly decreased the percentage of CD206(+) cells in breast cancer compared to controls[(6.08%±2.60%) vs(29.04%±5.86%), P<0.05]. CONCLUSION: The combination of lapatinib and chlorogenic acid can effectively inhibit macrophage M2 polarization and metastasis of breast cancer.


Sujet(s)
Acide chlorogénique/pharmacologie , Macrophages/effets des médicaments et des substances chimiques , Tumeurs expérimentales de la mamelle/traitement médicamenteux , Métastase tumorale/traitement médicamenteux , Quinazolines/pharmacologie , Animaux , Femelle , Lapatinib , Tumeurs du poumon/traitement médicamenteux , Tumeurs du poumon/secondaire , Souris
4.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 44(5): 500-5, 2015 09.
Article de Chinois | MEDLINE | ID: mdl-26713523

RÉSUMÉ

OBJECTIVE: To evaluate the anti-tumor effect of the combination of suberoylanilide hydroxamic acid(SAHA) with statins(lovastatin or simvastatin) on non-small cell lung carcinoma(NSCLC) cells. METHODS: Human NSCLC A549 cells were treated with SAHA in combination of lovastatin or simvastatin. The cell growth was analyzed by SRB method, and the apoptosis of A549 cells was assessed by flow cytometer. The expression of cleaved poly-ADP-ribose polymerase(cleaved-PARP) and p21 protein was analyzed by Western-blotting when A549 cells were challenged with 2.5µmol/L SAHA and 5µmol/L lovastatin. RESULTS: Lovastatin and simvastatin synergized SAHA in the inhibition of A549 cells. SAHA induced apoptosis was also enhanced by lovastatin. Treatment with 2.5µmol/L SAHA significantly up-regulated the expression of p21 protein in 48 h, while the protein expression was reduced in combined treatment with 5µmol/L lovastatin. CONCLUSION: Statins can synergize the anti-tumor effect of SAHA in human NSCLC cells through a p21-dependent way.


Sujet(s)
Antinéoplasiques/pharmacologie , Apoptose , Carcinome pulmonaire non à petites cellules/anatomopathologie , Acides hydroxamiques/pharmacologie , Inhibiteurs de l'hydroxyméthylglutaryl-CoA réductase/pharmacologie , Lignée cellulaire tumorale/effets des médicaments et des substances chimiques , Prolifération cellulaire , Inhibiteur p21 de kinase cycline-dépendante/métabolisme , Humains , Poly(ADP-ribose) polymerases/métabolisme , Vorinostat
5.
Sci Rep ; 5: 13327, 2015 Aug 20.
Article de Anglais | MEDLINE | ID: mdl-26289919

RÉSUMÉ

Drug addiction is considered an aberrant form of learning, and drug-associated memories evoked by the presence of associated stimuli (drug context or drug-related cues) contribute to recurrent craving and reinstatement. Epigenetic changes mediated by DNA methyltransferase (DNMT) have been implicated in the reconsolidation of fear memory. Here, we investigated the role of DNMT activity in the reconsolidation of cocaine-associated memories. Rats were trained over 10 days to intravenously self-administer cocaine by nosepokes. Each injection was paired with a light/tone conditioned stimulus (CS). After acquisition of stable self-administration behaviour, rats underwent nosepoke extinction (10 d) followed by cue-induced reactivation and subsequent cue-induced and cocaine-priming + cue-induced reinstatement tests or subsequently tested to assess the strength of the cocaine-associated cue as a conditioned reinforcer to drive cocaine seeking behaviour. Bilateral intra-basolateral amygdala (BLA) infusion of the DNMT inhibitor5-azacytidine (5-AZA, 1 µg per side) immediately following reactivation decreased subsequent reinstatement induced by cues or cocaine priming as well as cue-maintained cocaine-seeking behaviour. In contrast, delayed intra-BLA infusion of 5-AZA 6 h after reactivation or 5-AZA infusion without reactivation had no effect on subsequent cue-induced reinstatement. These findings indicate that memory reconsolidation for a cocaine-paired stimulus depends critically on DNMT activity in the BLA.


Sujet(s)
Groupe nucléaire basolatéral/enzymologie , Cocaïne/pharmacologie , DNA (cytosine-5-)-methyltransferase/métabolisme , Mémoire/effets des médicaments et des substances chimiques , Animaux , Azacitidine/pharmacologie , Groupe nucléaire basolatéral/effets des médicaments et des substances chimiques , Comportement animal/effets des médicaments et des substances chimiques , DNA (cytosine-5-)-methyltransferase/antagonistes et inhibiteurs , Mâle , Rat Sprague-Dawley , 12476
6.
Heart Vessels ; 30(5): 669-74, 2015 Sep.
Article de Anglais | MEDLINE | ID: mdl-25260401

RÉSUMÉ

The aim of this study was to explore myocardial protection of early extracorporeal membrane oxygenation (ECMO) support for acute myocardial infarction with cardiogenic shock in pigs. 24 male pigs (34.6 ± 1.3 kg) were randomly divided into three groups-control group, drug therapy group, and ECMO group. Myocardial infarction model was created in drug therapy group and ECMO group by ligating coronary artery. When cardiogenic shock occurred, drugs were given in drug therapy group and ECMO began to work in ECMO group. The pigs were killed 24 h after cardiogenic shock. Compared with in drug therapy group, left ventricular end-diastolic pressure in ECMO group decreased significantly 6 h after ligation (P < 0.05). At the end of the experiments, LV - dp/dt among three groups was significantly different, drug therapy group < ECMO group < control group. There was no difference in LV + dp/dt between drug therapy group and ECMO group. Compared with drug group, myocardial infarct size of ECMO group did not reduce significantly, but myocardial enzyme and troponin-I decreased significantly. Compared with drug therapy, ECMO improves left ventricular diastolic function, and may improve systolic function. ECMO cannot reduce myocardial infarct size without revascularization, but may have positive effects on ischemic areas by avoiding further injuring.


Sujet(s)
Oxygénation extracorporelle sur oxygénateur à membrane/méthodes , Infarctus du myocarde/thérapie , Myocarde/anatomopathologie , Choc cardiogénique/thérapie , Animaux , Modèles animaux de maladie humaine , Études de suivi , Mâle , Infarctus du myocarde/complications , Infarctus du myocarde/physiopathologie , Myocarde/métabolisme , Choc cardiogénique/étiologie , Choc cardiogénique/physiopathologie , Débit systolique/physiologie , Suidae , Porc miniature , Facteurs temps , Fonction ventriculaire gauche/physiologie
7.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(4): 1135-40, 2013 Apr.
Article de Chinois | MEDLINE | ID: mdl-23841444

RÉSUMÉ

Visible-near infrared (Vis-NIR) reflectance spectroscopy, which is rapid, cost-effective, in-situ, nondestructive and without hazardous chemicals, is increasingly being used for prediction and digital soil mapping of soil organic matter (SOM). This method is the inevitable demand for precision agriculture and soil remote sensing mapping. In the present study, the Vis-NIR (350-2 500 nm) diffuse reflectance spectral collected by ASD FieldSpec Pro FR spectrometer was truncated by removing the noisy edge values below 400 nm and above 2 450 nm and then was transformed into apparent absorbance spectral using log(1/ R). Based on the relationship analysis between absorbance spectral, spectral indices and SOM, partial least squares regression (PLSR) model was applied to predict SOM, and finally the spatial variability of SOM was characterized by geostatistics method. The results indicated that good model was modeling from the characteristic bands (CB, R2 = 0.91, RPD = 3.28) of correlation coefficient more than 0. 5, the spectral index (SI) of normalized difference index (NDI, R2 0.90, RPD = 3.08), CB integrating SI with which a correlation coefficient was more than 0.5 (R2 = 0.87, RPD = 2.67), and total bands (TA, 400-2 450 nm, R2 = 0.95, RPD = 4.36). While the digital mapping of SOM produced by kriging and cokriging interpolation methods implied a better prediction result, showing similar spatial distribution with the measured SOM, indicating that it is feasible and reliable to use these spectral indices to predict and map the spatial variability.

8.
Asian Pac J Trop Med ; 5(4): 306-9, 2012 Apr.
Article de Anglais | MEDLINE | ID: mdl-22449523

RÉSUMÉ

OBJECTIVE: To investigate the cellular toxicity of isoniazid together with rifampicin and the metabolites of isoniazid on cultured QSG-7701 cells lines. METHODS: Isoniazid, rifampicin, mixture of rifampicin and isoniazid, acetylhydrazine, hydrazine were added in cultural media of QSG-7701 cells and cultured for 48 hours. The survival rate of cells was determined by MTT method. The cultural media and cells were collected and the activity of lactate dehydrogenase was detected by chromatometry. RESULTS: Compared with control group, the survival rate decreased significantly and the lactate dehydrogenase released from cell increased significantly in cells treated with isoniazid, rifampicin, acetylhydrazine, hydrazine. Hydrazine, the metabolite of isoniazid produced significant damage on hepatocytes in low concentration. CONCLUSIONS: Rifampicin together with rifampicin and metabolites of isoniazid produce cellular toxic effects and hydrazine may be the most toxiferous metabolite.


Sujet(s)
Antituberculeux/toxicité , Lésions hépatiques dues aux substances/étiologie , Hépatocytes/effets des médicaments et des substances chimiques , Isoniazide/toxicité , Rifampicine/toxicité , Analyse de variance , Études cas-témoins , Survie cellulaire/effets des médicaments et des substances chimiques , Cellules cultivées , Association médicamenteuse , Humains , L-Lactate dehydrogenase/métabolisme
9.
Cancer Lett ; 309(1): 27-36, 2011 Oct 01.
Article de Anglais | MEDLINE | ID: mdl-21664043

RÉSUMÉ

The present study showed that GDC-0941 potently sensitized breast cancer to ABT-737 in vitro and in vivo. ABT-737 exhibited limited lethality in breast cancer cells; however, when combined with GDC-0941, it displayed strong synergistic cytotoxicity and enhanced caspase-mediated apoptosis. GDC-0941 promoted proteasomal degradation of Mcl-1, of which the overexpression has been validated to confer ABT-737 resistance, thereby enhanced the anticancer efficacy of ABT-737. Furthermore, the combination of GDC-0941 and ABT-737 exerted increased anti-tumor efficacy on MDA-MB-231 xenograft models. Overall, our data described unprecedentedly the promising therapeutic potential and underlying mechanisms of combining GDC-0941 with ABT-737 in treating breast cancer.


Sujet(s)
Dérivés du biphényle/pharmacologie , Tumeurs du sein , Indazoles/pharmacologie , Nitrophénols/pharmacologie , Protéines proto-oncogènes c-bcl-2/métabolisme , Sulfonamides/pharmacologie , Animaux , Antinéoplasiques/pharmacologie , Apoptose/effets des médicaments et des substances chimiques , Tumeurs du sein/traitement médicamenteux , Tumeurs du sein/métabolisme , Tumeurs du sein/anatomopathologie , Caspases/métabolisme , Lignée cellulaire tumorale , Synergie des médicaments , Femelle , Humains , Souris , Souris nude , Protéine Mcl-1 , Transplantation tumorale , Inhibiteurs des phosphoinositide-3 kinases , Pipérazines/pharmacologie
10.
J Ethnopharmacol ; 128(1): 154-9, 2010 Mar 02.
Article de Anglais | MEDLINE | ID: mdl-20051258

RÉSUMÉ

ETHNOPHARMACOLOGICAL RELEVANCE: The radix of Acorus calamus L. (AC) is widely used in the therapy of diabetes in traditional folk medicine of America and Indonesia, and we previously reported the insulin sensitizing activity of the ethyl acetate fraction of AC (ACE). AIM OF THE STUDY: To investigate the insulin releasing and alpha-glucosidase inhibitory activity of ACE in vitro and in vivo. MATERIALS AND METHODS: Insulin releasing and alpha-glucosidase inhibitory effects of different fractions from AC were detected in vitro using HIT-T15 cell line and alpha-glucosidase enzyme. Furthermore, effects of ACE orally on serum glucose were detected in fasted and glucose/amylum challenged normal mice. RESULTS: AC and ACE increased insulin secretion in HIT-T15 cells as gliclazide did. As in vivo results, ACE (400 and 800 mg/kg) significantly decreased fasting serum glucose, and suppressed the increase of blood glucose levels after 2g/kg glucose loading in normal mice. In addition, ACE as a mixed-type inhibitor inhibited alpha-glucosidase activity in vitro with an IC(50) of 0.41 microg/ml, and 100mg/kg of it clearly reduced the increase of blood glucose levels after 5 g/kg amylum loading in normal mice. CONCLUSIONS: Apart from its insulin sensitizing effect, ACE may have hypoglycemic effects via mechanisms of insulin releasing and alpha-glucosidase inhibition, and thus improves postprandial hyperglycemia and cardiovascular complications.


Sujet(s)
Acétates/composition chimique , Acorus/composition chimique , Antienzymes/pharmacologie , Inhibiteurs des glycoside hydrolases , Insuline/métabolisme , Animaux , Glycémie/analyse , Lignée cellulaire , Techniques in vitro , Sécrétion d'insuline , Cinétique , Mâle , Souris , Souris de lignée ICR , Période post-prandiale
11.
Invest New Drugs ; 28(6): 800-11, 2010 Dec.
Article de Anglais | MEDLINE | ID: mdl-19789842

RÉSUMÉ

Previous study demonstrated that MONCPT, a topoisomerase I inhibitor, exhibited potent anti-proliferation and anti-angiogenesis activity in vitro and in vivo. In this study, we report the efficacy of MONCPT against the development of melanoma metastasis by an intravenous injection of green fluorescent protein-transfected mice melanoma carcinoma (B16F10-GFP) cells in C57BL/6 mice. MONCPT (2.0, 5.0 and 12.5 mg/kg/2 days) markedly decreased B16F10-GFP pulmonary metastases by 12.8%, 53.1% and 76.3%, respectively; whereas higher doses of MONCPT (31.0 mg/kg/2 days) significantly inhibited the tumor growth of B16F10 xenograft model. In the in vitro experiment, MONCPT suppressed the B16F10-GFP cell invasion and migration without affecting cell survival. Further studies demonstrated that MONCPT decreased the secretion of matrix metalloproteinase (MMP)-9 and VEGF, and reduced the protein expression of HIF-1α as well as the phosphorylation level of ERK in B16F10-GFP cells. These in vivo and in vitro results indicate that MONCPT possesses both the potent antimetastatic ability and the tumor growth-inhibition activity, and the dual function promises MONCPT as a potential therapeutic agent for tumor metastasis and tumor growth of melanoma carcinoma.


Sujet(s)
Camptothécine/analogues et dérivés , Modèles animaux de maladie humaine , Mélanome/traitement médicamenteux , Mélanome/anatomopathologie , Métastase tumorale/traitement médicamenteux , Animaux , Camptothécine/pharmacologie , Camptothécine/usage thérapeutique , Adhérence cellulaire/effets des médicaments et des substances chimiques , Hypoxie cellulaire/effets des médicaments et des substances chimiques , Lignée cellulaire tumorale , Mouvement cellulaire/effets des médicaments et des substances chimiques , Prolifération cellulaire/effets des médicaments et des substances chimiques , Séparation cellulaire , Tests de criblage d'agents antitumoraux , Extracellular Signal-Regulated MAP Kinases/métabolisme , Femelle , Protéines à fluorescence verte/métabolisme , Sous-unité alpha du facteur-1 induit par l'hypoxie/métabolisme , Tumeurs du poumon/anatomopathologie , Tumeurs du poumon/secondaire , Mélanome/enzymologie , Souris , Souris de lignée C57BL , Invasion tumorale , Métastase tumorale/anatomopathologie , Phosphorylation/effets des médicaments et des substances chimiques , Protéines proto-oncogènes c-akt/métabolisme , Transduction du signal/effets des médicaments et des substances chimiques , Transduction génétique , Facteur de croissance endothéliale vasculaire de type A/métabolisme
12.
Yao Xue Xue Bao ; 40(11): 1037-40, 2005 Nov.
Article de Chinois | MEDLINE | ID: mdl-16499091

RÉSUMÉ

AIM: To establish the rat model of morphine-induced conditioned place preference (CPP) and to investigate the effects of morphine psychical dependence on the levels of neurosteroids in rat brain. METHODS: Rats were ip administered morphine 5 mg x kg(-1) for 10 days to induce CPP in morphine group. The concentrations of dehydroepiandrosterone (DHEA), pregnenolone (PREG), allopregnanolone (AP), dehydroepiandrosterone sulfate (DS) and pregnenolone sulfate (PS) in nucleus accumbens (Nac), hypothalamus (Ht), amygdale (A) and plasma of rats were determined with liquid chromatography-negative atmospheric pressure ionization mass spectrometry (LC-MS). RESULTS: Trained with morphine for 10 days resulted in the acquisition of CPP in morphine group with the time that the rats spent in drug-pairing room was longer than that of control group. Compared with control group, morphine treatment could significantly decrease the contents of DHEA in Nac and plasma, decrease that of PREG in Ht. CONCLUSION: Morphine could induce the CPP in rats and affected the contents of some neurosteroids in rat brain, which suggests that endogenous neurosteroids might he related to the development of morphine dependence.


Sujet(s)
Encéphale/métabolisme , Déhydroépiandrostérone/métabolisme , Dépendance à la morphine/métabolisme , Prégnénolone/métabolisme , Amygdale (système limbique)/métabolisme , Animaux , Conditionnement opérant/physiologie , Déhydroépiandrostérone/sang , Sulfate de déhydroépiandrostérone/sang , Sulfate de déhydroépiandrostérone/métabolisme , Hypothalamus/métabolisme , Mâle , Noyau accumbens/métabolisme , Prégnanolone/sang , Prégnanolone/métabolisme , Prégnénolone/sang , Rats , Rat Sprague-Dawley
13.
Contraception ; 68(4): 289-95, 2003 Oct.
Article de Anglais | MEDLINE | ID: mdl-14572893

RÉSUMÉ

This study evaluated the effectiveness and acute toxicity of DL111-IT combined with mifepristone (RU486) and misoprostol (MISO) on early pregnancy termination. In the pregnant rats experiments, the ED(50) values of RU486 in two-drug combinations were 0.16 (combined with DL111-IT) and 0.40 (combined with MISO) mg x kg(-1) x d(-1), while in three-drug combination treatment group (DL111-IT 9.0 mg x kg(-1) (

Sujet(s)
Abortifs non stéroïdiens/toxicité , Abortifs stéroïdiens/administration et posologie , Avortement provoqué , Mifépristone/administration et posologie , Misoprostol/administration et posologie , Triazoles/toxicité , Animaux , Columbidae , Synergie des médicaments , Association de médicaments , Femelle , Cochons d'Inde , Mâle , Souris , Grossesse , Premier trimestre de grossesse , Rats , Rat Sprague-Dawley , Utérus/effets des médicaments et des substances chimiques , Vomissement/induit chimiquement
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE