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Bougeard A, Guay Hottin1 R, Houde V, Jean T, Piront T, Potvin S, Bernard P, Tourjman V, De Benedictis L, Orban P. Le phénotypage digital pour une pratique clinique en santé mentale mieux informée. smq 2021. [DOI: 10.7202/1081513ar] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Objectifs Cette revue trouve sa motivation dans l’observation que la prise de décision clinique en santé mentale est limitée par la nature des mesures typiquement obtenues lors de l’entretien clinique et la difficulté des cliniciens à produire des prédictions justes sur les états mentaux futurs des patients. L’objectif est de présenter un survol représentatif du potentiel du phénotypage digital couplé à l’apprentissage automatique pour répondre à cette limitation, tout en en soulignant les faiblesses actuelles.
Méthode Au travers d’une revue narrative de la littérature non systématique, nous identifions les avancées technologiques qui permettent de quantifier, instant après instant et dans le milieu de vie naturel, le phénotype humain au moyen du téléphone intelligent dans diverses populations psychiatriques. Des travaux pertinents sont également sélectionnés afin de déterminer l’utilité et les limitations de l’apprentissage automatique pour guider les prédictions et la prise de décision clinique. Finalement, la littérature est explorée pour évaluer les barrières actuelles à l’adoption de tels outils.
Résultats Bien qu’émergeant d’un champ de recherche récent, de très nombreux travaux soulignent déjà la valeur des mesures extraites des senseurs du téléphone intelligent pour caractériser le phénotype humain dans les sphères comportementale, cognitive, émotionnelle et sociale, toutes étant affectées par les troubles mentaux. L’apprentissage automatique permet d’utiles et justes prédictions cliniques basées sur ces mesures, mais souffre d’un manque d’interprétabilité qui freinera son emploi prochain dans la pratique clinique. Du reste, plusieurs barrières identifiées tant du côté du patient que du clinicien freinent actuellement l’adoption de ce type d’outils de suivi et d’aide à la décision clinique.
Conclusion Le phénotypage digital couplé à l’apprentissage automatique apparaît fort prometteur pour améliorer la pratique clinique en santé mentale. La jeunesse de ces nouveaux outils technologiques requiert cependant un nécessaire processus de maturation qui devra être encadré par les différents acteurs concernés pour que ces promesses puissent être pleinement réalisées.
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Affiliation(s)
- Alan Bougeard
- Étudiant, Centre de recherche de l’Institut universitaire en santé mentale de Montréal
| | - Rose Guay Hottin1
- Étudiante, Centre de recherche de l’Institut universitaire en santé mentale de Montréal
| | - Valérie Houde
- M.D., étudiante, Centre de recherche de l’Institut universitaire en santé mentale de Montréal
| | - Thierry Jean
- Étudiant, Centre de recherche de l’Institut universitaire en santé mentale de Montréal
| | - Thibault Piront
- Professionnel de recherche, Centre de recherche de l’Institut universitaire en santé mentale de Montréal
| | - Stéphane Potvin
- Ph. D., chercheur, Centre de recherche de l’Institut universitaire en santé mentale de Montréal – professeur sous octroi titulaire, Département de psychiatrie et d’addictologie, Université de Montréal
| | - Paquito Bernard
- Ph. D., chercheur, Centre de recherche de l’Institut universitaire en santé mentale de Montréal – professeur régulier, Département des sciences de l’activité physique, Université du Québec à Montréal
| | - Valérie Tourjman
- M.D., psychiatre, Institut universitaire en santé mentale de Montréal – professeure agrégée de clinique, Département de psychiatrie et d’addictologie, Université de Montréal
| | - Luigi De Benedictis
- M.D., psychiatre, Institut universitaire en santé mentale de Montréal – professeur adjoint de clinique, Département de psychiatrie et d’addictologie, Université de Montréal
| | - Pierre Orban
- Ph. D., chercheur, Centre de recherche de l’Institut universitaire en santé mentale de Montréal – professeur sous octroi adjoint, Département de psychiatrie et d’addictologie, Université de Montréal
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Bougeard A, Guay Hottin R, Houde V, Jean T, Piront T, Potvin S, Bernard P, Tourjman V, De Benedictis L, Orban P. [Improved Mental Health Clinical Practice Informed by Digital Phenotyping]. Sante Ment Que 2021; 46:135-136. [PMID: 34597492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Objectives This review is motivated by the observation that clinical decision-making in mental health is limited by the nature of the measures obtained in conventional clinical interviews and the difficulty for clinicians to make accurate predictions about their patients' future mental states. Our objective is to offer a representative overview of the potential of digital phenotyping coupled with machine learning to address this limitation, while highlighting its own current weaknesses. Methods Through a non-systematic narrative review of the literature, we identify the technological developments that make it possible to quantify, moment by moment and in ecologically valid settings, the human phenotype in various psychiatric populations using the smartphone. Relevant work is also selected in order to determine the usefulness and limitations of machine learning to guide predictions and clinical decision-making. Finally, the literature is explored to assess current barriers to the adoption of such tools. Results Although emerging from a recent field of research, a large body of work already highlights the value of measurements extracted from smartphone sensors in characterizing the human phenotype in behavioral, cognitive, emotional and social spheres that are all impacted by mental disorders. Machine learning permits useful and accurate clinical predictions based on such measures, but suffers from a lack of interpretability that will hamper its use in clinical practice in the near future. Moreover, several barriers identified both on the patient and clinician sides currently hamper the adoption of this type of monitoring and clinical decision support tools. Conclusion Digital phenotyping coupled with machine learning shows great promise for improving clinical practice in mental health. However, the youth of these new technological tools requires a necessary maturation process to be guided by the various concerned actors so that these promises can be fully realized.
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Affiliation(s)
- Alan Bougeard
- Centre de recherche de l'Institut universitaire en santé mentale de Montréal
| | - Rose Guay Hottin
- Centre de recherche de l'Institut universitaire en santé mentale de Montréal
| | - Valérie Houde
- Centre de recherche de l'Institut universitaire en santé mentale de Montréal
| | - Thierry Jean
- Centre de recherche de l'Institut universitaire en santé mentale de Montréal
| | - Thibault Piront
- Centre de recherche de l'Institut universitaire en santé mentale de Montréal
| | - Stéphane Potvin
- Centre de recherche de l'Institut universitaire en santé mentale de Montréal ; Département de psychiatrie et d'addictologie, Université de Montréal
| | - Paquito Bernard
- Centre de recherche de l'Institut universitaire en santé mentale de Montréal ; Département des sciences de l'activité physique, Université du Québec à Montréal
| | - Valérie Tourjman
- Institut universitaire en santé mentale de Montréal ; Département de psychiatrie et d'addictologie, Université de Montréal
| | - Luigi De Benedictis
- Institut universitaire en santé mentale de Montréal ; Département de psychiatrie et d'addictologie, Université de Montréal
| | - Pierre Orban
- Centre de recherche de l'Institut universitaire en santé mentale de Montréal ; Département de psychiatrie et d'addictologie, Université de Montréal
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Sadigh N, Jean T. M233 DIAGNOSIS OF COMPLEMENT 7 DEFICIENCY FOLLOWING VIRAL MENINGITIS. Ann Allergy Asthma Immunol 2020. [DOI: 10.1016/j.anai.2020.08.261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Panganiban C, Narsai T, Reeder D, Naderi A, Levy D, Hsieh Y, Wang B, Jean T. M152 SCHNITZLER’S SYNDROME: A RARE MIMICKER OF CHRONIC URTICARIA. Ann Allergy Asthma Immunol 2020. [DOI: 10.1016/j.anai.2020.08.224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ziyar A, Gharib A, Jean T, Hsieh Y, Levy D. M152 TREATMENT OF DELAYED PRESSURE ANGIOEDEMA WITH OMALIZUMAB IN A 40-YEAR-OLD WOMAN. Ann Allergy Asthma Immunol 2019. [DOI: 10.1016/j.anai.2019.08.152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Eng V, Jean T, Pourang D, Ramanathan A, Eichhorn K, Hever A, Samant S. P264 IGG4-related orbital disease with anca positivity: a case report. Ann Allergy Asthma Immunol 2017. [DOI: 10.1016/j.anai.2017.08.180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Jean T, Eng V, Sheikh J, Samant S. OR101 Outcomes of patients with aspirin-exacerbated respiratory disease on omalizumab. Ann Allergy Asthma Immunol 2017. [DOI: 10.1016/j.anai.2017.08.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Masson F, Néliat G, Drieu K, Defeudis FV, Jean T. Effects of an extract ofGinkgo bilobaOn the action potential and associated transmembrane ionic currents in mammalian cardiac myocytes: Inhibition of isoproterenol-induced chloride current. Drug Dev Res 2004. [DOI: 10.1002/ddr.430320106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Bellamy J, Jean T, Bendjaballah F. [A further case of tracheal paraganglioma]. Rev Mal Respir 1999; 16:1143-6. [PMID: 10637913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Paragangliomas, or chemodectomas, are neuro-endocrine tumors of the neural type, derived from extra-adrenal paraganglia. Tracheal localizations are rare. We report the case of a patient with a paraganglioma of the upper part of the trachea. The tumor was totally removed by means of the resection of the subglottic trachea and anastomosis. Surgery is the treatment of such lesions, but can be difficult in cases of subglottic or juxta-carinal localizations.
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Affiliation(s)
- J Bellamy
- Hôpital privé Claude-Galien, Quincy-sous-Sénart
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Caronia F, Jean T, Saltiel JC, Bellamy J. [Two new cases of autonomous ectopic goiter]. Rev Pneumol Clin 1998; 54:34-37. [PMID: 9769984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We observed two cases of autonomous intrathoracic goiter in patients with no past history of thyroidectomy. After resection, the surgical specimens confirmed the non-malignant nature of the goiter. We discuss the literature on management of autonomous intrathoracic goiter.
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Affiliation(s)
- F Caronia
- Centre Val d'Or Saint Cloud, Saint Cloud
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Galizzi JP, Bodinier MC, Chapelain B, Ly SM, Coussy L, Giraud S, Neliat G, Jean T. Up-regulation of [3H]-des-Arg10-kallidin binding to the bradykinin B1 receptor by interleukin-1 beta in isolated smooth muscle cells: correlation with B1 agonist-induced PGI2 production. Br J Pharmacol 1994; 113:389-94. [PMID: 7834189 PMCID: PMC1510113 DOI: 10.1111/j.1476-5381.1994.tb17001.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
1. Binding of the specific bradykinin B1 receptor agonist, [3H]-des-Arg10-kallidin (-KD) was investigated in smooth muscle cells (SMC) isolated from rabbit mesenteric arteries (RMA). 2. [3H]-des-Arg10-KD specifically bound to interleukin-1 (IL-1)-treated RMA-SMC in a saturable fashion with an equilibrium dissociation constant (KD) of 0.3-0.5 nM. The number of binding sites per cell was 20,000-35,000. Kinins inhibited [3H]-des-Arg10-KD binding to RMA-SMC with an order of potency very similar to that observed in typical B1 specific bioassays: des-Arg9-bradykinin (BK) approximately KD >> BK. Furthermore, the B1 receptor antagonist [Leu8]des-Arg9-BK inhibited [3H]-des-Arg10-KD binding with an IC50 of 43 nM as expected for its effect at B1 receptors. The B2 receptor antagonists, NPC 567 and Hoe 140 only affected [3H]-des-Arg10-KD binding at very high concentrations (IC50 = 0.8 microM and IC50 > 10 microM, respectively). 3. Des-Arg9-BK (B1 agonist) and [Hyp3]Tyr(Me)8-BK (B2 agonist) did not induce prostacyclin (PGI2) production by RMA-SMC. Lipopolysaccharide (LPS) treatment of the cells did not affect the B1 agonist response whereas IL-1 beta treatment produced a 7 fold increase in des-Arg9-BK-stimulated PGI2 production. IL-1 beta also stimulated the response to B2 agonists. 4. Des-Arg9-BK-induced PGI2 secretion in IL-1-primed RMA-SMC was mediated by B1 receptors since it was inhibited by [Leu8]des-Arg9-BK (IC50 = 56-73 nM) but not by Hoe 140. High concentrations of NPC 567 (IC5o = 2.4 micro M) were required to inhibit PGI2 production induced by B1 agonists.5. IL- 1-treated RMA-SMC displayed a 5 fold increase in the number of B1 receptors without modification of the affinity constant, thus establishing a possible relationship between the receptor density and the IL-i-primed B1 response.6. LPS treatment of the cells induced a 4 fold increase in B1 receptor number without modifying PGI2 secretion. This observation suggests that IL-1 but not LPS, in addition to increase in the number of receptors, signals the cell to permit the coupling of B1 receptors to the PLA2/cyclo-oxygenase pathway.
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Jean T, Bodinier MC. Mediators involved in inflammation: effects of Daflon 500 mg on their release. Angiology 1994; 45:554-9. [PMID: 8203787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Each step of an inflammatory reaction is triggered by one or several chemical or biological mediators such as arachidonic acid derivatives (prostaglandins [PG], leukotrienes [LT], or thromboxanes [TX]), vasoactive amines (histamine or serotonin), and oxygen free radicals (superoxide ion, O2-, or hydrogen peroxide, H2O2). In perivenous inflammation, these mediators play a prominent role in favoring vasodilatation (histamine), increasing membrane permeability (PGE2, histamine, free radicals) and providing a chemotactic signal for specialized cells, ie, neutrophil polynuclears, macrophages, lymphocytes (LTB4, free radicals). The antiinflammatory effects of Daflon 500 mg,* a micronized purified flavonoid fraction (90% diosmin, 10% hesperidin), were studied in different in vivo and in vitro models. In a model of inflammatory granuloma in the rat, Daflon 500 mg (100 mg/kg, orally) reduced edema formation and inhibited the synthesis for PGE2 (78.5%), PGF2 alpha (45.2%) and TXB2 (59.5%) (Damon et al, Arzneim-Forsch/Drug Res 37:1149-1153, 1987). Intravenous injection of Daflon 500 mg (25 and 50 mg/kg) reduced the hyperglycemia induced by injection of alloxan in rat. This effect of Daflon 500 mg was linked to its ability to scavenge active oxygen radicals, demonstrated in vitro using human neutrophils (Lonchampt et al, Arzneim-forsch/Drug Res 39:882-885, 1989) or mouse peritoneal macrophages (Bodinier et al, manuscript in preparation) stimulated by zymosan. The free radical scavenger effect of Daflon 500 mg is observed at concentrations ranging from 10(-7) M to 10(-4) M, with half-maximal effect between 10(-6) M and 10(-5) M. Thus, Daflon 500 mg behaves as a potent protective agent against inflammatory disorders. These properties may explain, at least in part, the clinical activity of Daflon 500 mg and justify its therapeutic use.
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Affiliation(s)
- T Jean
- CEREP, Celle l'Evescault, France
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Vasseur M, Jean T, DeFeudis FV, Drieu K. Effects of repeated treatments with an extract of Ginkgo biloba (EGb 761), bilobalide and ginkgolide B on the electrical activity of pancreatic beta cells of normal or alloxan-diabetic mice: an ex vivo study with intracellular microelectrodes. Gen Pharmacol 1994; 25:31-46. [PMID: 8026711 DOI: 10.1016/0306-3623(94)90007-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
1. The effects of repeated (5-day) treatments with an extract of Ginkgo biloba leaves (EGb 761), bilobalide, and ginkgolide B on the in vitro electrical activity of insulin-secreting pancreatic beta cells of mice have been examined using intracellular microelectrodes. 2. EGb 761 (200 mg/kg/day, p.o.) protected beta cells against the toxic effects of alloxan (50 mg/kg, i.v.), an effect characterized by a restoration of membrane potential (Vr) and an increase in spike frequency (Fs/30), an indicator of insulin secretion. 3. Treatment of non-diabetic mice with EGb 761 (200 mg/kg/day, p.o.) increased Fs/30 of their beta cells, as tested by in vitro exposure of the cells to 11.1 mM glucose, an effect that also occurred with bilobalide (8 mg/kg/day, i.p.) but not with ginkgolide B (4 mg/kg/day, i.p.). 4. Since bilobalide and ginkgolide B caused opposite effects on the sensitivity of beta cells to glucose, the stimulatory effect of EGb 761 on Fs/30 may be attributed to its content of bilobalide. 5. In contrast to its ex vivo effect, the direct in vitro effect of EGb 761 (10 and 25 micrograms/ml) on beta cells favors a decrease in electrical activity, indicating that its in vivo action might be indirect (e.g. via the formation of an active metabolite).
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Affiliation(s)
- M Vasseur
- Celaster Etudes Recherche et Production, Celle l'Evescault, France
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Abstract
Incubation of rabbit aortic rings with interleukin-1 (100 U/ml) in vitro led to a depressed contractile response to norepinephrine, whether the endothelium was present or not. In both cases norepinephrine-induced contraction was restored in the presence of NG-methyl-L-arginine (300 microM), an inhibitor of nitric oxide synthesis. In interleukin-1-treated rings precontracted with norepinephrine (1 microM), the relaxing response to acetylcholine was totally suppressed independently on the presence of endothelium. High concentrations of acetylcholine (greater than 1 microM) induced a slight contraction which was of lower amplitude than that obtained in control endothelium-denuded rings and was increased in the presence of NG-methyl-L-arginine. These results show that interleukin-1 (i) affects not only vascular contraction but also relaxation and (ii) involves both endothelial and non-endothelial factors. These observations suggest an impairment of the whole vascular reactivity during septic shock.
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Affiliation(s)
- R Robert
- CEREP, Celle l'Evescault, France
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Czermak M, Jean T. [Von Economo-Cruchet lethargic encephalitis and its relation to HIV infection]. Encephale 1990; 16:375-82. [PMID: 2176147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The AIDS epidemic is currently considered to be the first retroviral disease in humans. However, in the large volume of work on von Economo-Cruchet's encephalitis lethargica, the authors reveal a series of common points between both diseases. The progress of both diseases is identical at every stage, with neurotropism, premature psychological disorders, mononucleasic syndrome, similar somatic manifestations of the viral attack and terminal dementia. The anatomo-pathological and epidemiological data, along with the hypothesis that encephalitis lethargica is sexually transmitted, reinforce the idea of a relationship between the two diseases. The interest which would be aroused by the discovery of a viral origin of encephalitis lethargica and the resulting experimental elements seem to make it worthwhile leaving the question open in order to find a precise answer. We are calling on all our colleagues in basic research to seek a solution to what we think is an essential question.
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Affiliation(s)
- M Czermak
- Psychiatre des Hôpitaux, Hôpital Henri Rousselle, Paris
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Jean T, Bodinier M, Perdrix L, Labrid C. In vitro studies of S5682 Interferences with histamine release, LTB4 formatton and free-radical generation. Eur J Pharmacol 1990. [DOI: 10.1016/0014-2999(90)93796-s] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
The effect of GTP on Ca2+ uptake and release was studied in a microsomal fraction isolated from neuroblastoma x glioma hybrid NG108-15 cells. GTP did not alter the ATP-dependent initial uptake of Ca2+ but markedly enhanced the efflux of Ca2+ from microsomes. GTP-dependent Ca2+ release requires the presence of millimolar concentration of Mg2+. The effect of GTP was not mimicked by other nucleotides and was competitively blocked by the thiophosphate analogue of GTP, GTP gamma S but not by the non-hydrolyzable nucleotide GMP-PNP. Addition of an inhibiting concentration of GTP gamma S after completion of GTP-induced calcium release did not result in a re-uptake of Ca2+, showing the irreversibility of the releasing effect of GTP. Our data are consistent with the hypothesis of Ca2+-dependent GTP-induced opening of a channel responsible for vectorial transport of Ca2+ ions from one intracellular compartment to another. A model is proposed suggesting that the GTP-binding protein is a GTP-specific diacylglycerol kinase.
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Affiliation(s)
- T Jean
- Laboratory of Biochemistry, National Cancer Institute, Bethesda, MD 20892
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Chassande O, Frelin C, Farahifar D, Jean T, Lazdunski M. The Na+/K+/Cl- cotransport in C6 glioma cells. Properties and role in volume regulation. Eur J Biochem 1988; 171:425-33. [PMID: 3345741 DOI: 10.1111/j.1432-1033.1988.tb13807.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The role of the Na+/K+/Cl- cotransporter in the regulation of the volume of C6 astrocytoma cells was analyzed using isotopic fluxes and cell cytometry measurements of the cell volume. The system was inhibited by 'loop diuretics' with the following order of potency: benzmetanide greater than bumetanide greater than piretanide greater than furosemide. Under physiological conditions of osmolarity of the incubation media, equal rates of bumetanide-sensitive inward and outward K+ fluxes were observed. Blockade of the Na+/K+/Cl- cotransporter with bumetanide did not lead to a modification in the mean cell volume. When C6 cells were incubated in an hyperosmotic solution, a cell shrinkage was observed. It was accompanied by a twofold increase in the activity of the Na+/K+/Cl- cotransport, which then catalyzed the net influx of K+. In spite of this increased activity, no cell swelling could be measured. Incubation of the cells in an iso-osmotic medium deprived of either Na+, K+ or Cl- also produced cell shrinkage. Large activations (up to tenfold) of the Na+/K+/Cl- cotransport together with a cell swelling back to the normal volume were observed upon returning ion-deprived C6 cells to a physiological solution. This cell swelling was completely prevented in the presence of bumetanide. It is concluded that the Na+/K+/Cl- cotransport system is one of the transport systems involved in volume regulation of glial cells. The system can either be physiologically quiescent or active depending on the conditions used. A distinct volume regulating mechanism is the Na+/H+ exchange system.
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Affiliation(s)
- O Chassande
- Centre de Biochimie, Centre National de la Recherche Scientifique, Nice, France
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Jean T, Klee CB. Calcium modulation of inositol 1,4,5-trisphosphate-induced calcium release from neuroblastoma x glioma hybrid (NG108-15) microsomes. J Biol Chem 1986; 261:16414-20. [PMID: 3491073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Subcellular fractions of neuroblastoma x glioma (NG108-15) hybrid cells were used to study the mechanism of inositol 1,4,5-trisphosphate-induced calcium release. A microsomal fraction, enriched in endoplasmic reticulum and plasma membranes and almost devoid of mitochondria, was the most active in inositol trisphosphate- or GTP-dependent release of calcium. Neither GTP nor inositol 1,4,5-trisphosphate affected the calcium efflux mediated by the other reagent, suggesting that inositol trisphosphate and GTP act on different calcium-sequestrating vesicles. The stimulation of calcium release by GTP was relatively slow (t1/2 = 90 s), dependent on polyethyleneglycol, and greater at 2 X 10(-5) M calcium (5 nmol X min-1 X mg-1) than at 10(-6) M calcium (0.8 nmol X min-1 X mg-1). The inositol trisphosphate-induced calcium efflux was not mimicked by inositol monophosphate; it was fast (t1/2 less than 10 s) and unaffected by 3% polyethyleneglycol. The amount of calcium released by inositol trisphosphate was greatest at 10(-6) M external calcium (1 nmol X min-1 X mg-1) and it was undetectable at 2 X 10(-5) M calcium. A feedback inhibition of the inositol trisphosphate-induced calcium release by cytoplasmic calcium provides a safety mechanism preventing deleterious effects of abnormally high calcium levels.
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Frelin C, Barbry P, Green RD, Jean T, Vigne P, Lazdunski M. The Na+/H+ antiport of eukaryotic cells: relationship between the kinetic properties of the system and its physiological function. Biochimie 1986; 68:1279-85. [PMID: 3024744 DOI: 10.1016/s0300-9084(86)80079-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The Na+/H+ antiport is present in the plasma membrane of virtually all vertebrate cells and it plays a central role in cell homeostasis. The pharmacological properties and the characteristics of the interaction of extracellular Na+, Li+, H+ and of intracellular H+ with the Na+/H+ antiport are reviewed herein. The kinetic properties of the system are shown to be essential for defining its four main physiological functions: transepithelial ion transport, control of the pHi, control of the intracellular Na+ concentration, and control of the cell volume. The activity of the Na+/H+ antiport can be modulated by a large number of effectors which are thought to act via protein kinases. At least three mechanisms of activation of the Na+/H+ exchanger are defined from the analysis of the kinetic properties of the system. Activation of the Na+/H+ antiport leads to very different consequences, depending upon the activity of other ion transporting systems in the membrane.
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Jean T, Klee CB. Calcium modulation of inositol 1,4,5-trisphosphate-induced calcium release from neuroblastoma x glioma hybrid (NG108-15) microsomes. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)66582-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Jean T, Frelin C, Vigne P, Lazdunski M. The Na+/H+ exchange system in glial cell lines. Properties and activation by an hyperosmotic shock. Eur J Biochem 1986; 160:211-9. [PMID: 3021452 DOI: 10.1111/j.1432-1033.1986.tb09959.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The properties of the Na+/H+ exchange system in the glial cell lines C6 and NN were studied from 22Na+ uptake experiments and measurements of the internal pH (pHi) using intracellularly trapped biscarboxyethyl-carboxyfluorescein. In both cell types, the Na+/H+ exchanger is the major mechanism by which cells recover their pHi after an intracellular acidification. The exchanger is inhibited by amiloride and its derivatives. The pharmacological profile (ethylisopropylamiloride greater than amiloride greater than benzamil) is identical for the two cell lines. Both Na+ and Li+ can be exchanged for H+. Increasing the external pH increases the activity of the exchanger in the two cell lines. In NN cells the external pH dependence of the exchanger is independent of the pHi. In contrast, in C6 cells, changing the pHi value from 7.0 to 6.5 produces a pH shift of 0.6 pH units in the external pH dependence of the exchanger in the acidic range. Decreasing pHi activates the Na+/H+ exchanger in both cell lines. Increasing the osmolarity of the external medium with mannitol produces an activation of the exchanger in C6 cells, which leads to a cell alkalinization. Mannitol action on 22Na+ uptake and the pHi were not observed in the presence of amiloride derivatives. Mannitol produces a modification of the properties of interaction of the antiport with both internal and external H+. It shifts the pHi dependence of the system to the alkaline range and the external pH (pHo) dependence to the acidic range. It also suppresses the interdependence of pHi and pHo controls of the exchanger's activity. NN cells that possess an Na+/H+ exchange system with different properties do not respond to mannitol by an increased activity of the Na+/H+ exchanger. The action of mannitol on C6 cells is unlikely to be mediated by an activation of protein kinase C.
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Vigne P, Jean T, Barbry P, Frelin C, Fine LG, Lazdunski M. [3H]Ethylpropylamiloride, a ligand to analyze the properties of the Na+/H+ exchange system in the membranes of normal and hypertrophied kidneys. J Biol Chem 1985; 260:14120-5. [PMID: 2997194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
[3H]Ethylpropylamiloride is a useful radioactive label to identify the Na+/H+ exchange system (Vigne, P., Frelin, C., Audinot, M., Borsotto, M., Cragoe, E. J., and Lazdunski, M. (1984) EMBO J. 3, 2647-2651). This paper extends the analysis of the properties of interaction of [3H]ethylpropylamiloride with the exchanger and describes its use with hypertrophied kidneys. [3H]Ethylpropylamiloride-binding sites copurify with the luminal membrane marker alkaline phosphatase but not with the basolateral membrane marker (Na+,K+)ATPase, thus indicating an asymmetric distribution of the Na+/H+ exchanger. Specific [3H]ethylpropylamiloride binding is dependent on pH. The pH dependency indicates that an ionizable function with a pKapp of 7.0 is essential in the association of the amiloride derivative. H+ acts competitively on [3H]ethylpropylamiloride binding; Na+, Li+, or cholinium ions have no effect on the association. Compensatory adaptation of the kidney to chronic reduction of renal mass is accompanied by a 1.7-fold increase in the activity of the Na+/H+ exchange system. Properties of interaction of internal and external pH with the Na+/H+ exchanger of normal and hypertrophied kidneys are identical. Titration of [3H]ethylpropylamiloride-binding sites in normal and hypertrophied kidneys suggests that the increased activity of the Na+/H+ exchange system is not accompanied by an increased concentration of exchangers.
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Jean T, Frelin C, Vigne P, Barbry P, Lazdunski M. Biochemical properties of the Na+/H+ exchange system in rat brain synaptosomes. Interdependence of internal and external pH control of the exchange activity. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(17)39292-x] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Jean T, Poujeol P, Ripoche P. Taurine transport in brush border membrane vesicles isolated from hyper- and normotaurinuric mouse kidney. Ren Physiol 1984; 7:349-56. [PMID: 6505373 DOI: 10.1159/000172957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The mouse strain C57BL is characterized by a high urinary fractional excretion of taurine. Hypertaurinuric [tau(-)] C57BL mice and three normal taurine 'excretors' [tau(+)]-Swiss, A/J, and C3H-were compared. Clearance experiments showed that fractional excretion of taurine was 4-8 times higher in C57BL relative to the other strains. Transport studies performed in brush border membrane vesicles, isolated from C57BL and C3H mouse renal cortex, showed that D-glucose uptake was similar in both strains while the taurine uptake appeared to be faster in tau(+) than in tau(-) mice. This difference was observed only in the presence of an inwardly directed NaCl gradient. The comparison of kinetic parameters showed a significant difference of apparent Km values: 90.8 +/- 11.4 microM in tau(+) mice vs. 129.5 +/- 17.1 microM in tau(-) mice. Jmax were not significantly different in both strains. These observations suggest a lower affinity of the taurine brush border membrane carrier in the hypertaurinuric strain as compared to the normotaurinuric mice. It is concluded that, in addition to a possible alteration of peritubular taurine efflux described by Rozen et al. (1983), a defect of taurine transport at the luminal membrane cannot be excluded and could account for the hypertaurinuria of the C57BL mice.
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Lelievre-Pegorier M, Jean T, Ripoche P, Poujeol P. Transport of phosphate, D-glucose, and L-valine in newborn rat kidney brush border. Am J Physiol 1983; 245:F367-73. [PMID: 6614176 DOI: 10.1152/ajprenal.1983.245.3.f367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Jean T, Ripoche P, Poujeol P. A sodium-independent mechanism for L-arginine uptake by rat renal brush border membrane vesicles. Membr Biochem 1983; 5:1-18. [PMID: 6645978 DOI: 10.3109/09687688309149630] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
L-arginine accumulation in renal cortex slices or in brush border membrane vesicles differs from that of neutral amino acids and sugars, since it can occur despite a lack of sodium in the incubation medium. L-arginine uptake was measured under different conditions in order to determine the relative importance of the Na+-independent component of this transport. In contrast to D-glucose, which was accumulated into the vesicles only in the presence of a NaCl gradient, the accumulation of L-arginine was induced by NaCl, LiCl, KCl, or choline Cl gradients. The uptakes of L-arginine and D-glucose wer proportional to the membrane potential (inside less than 0), but the presence of Na+ was not required for the L-arginine uptake. No difference was observed in Kj values of the L-arginine uptake measured with low or high concentration of salt (Li+ or Na+). Jmax were also in the same range of magnitude. An influx of D-glucose or L-alanine (Na+-cotransported molecules) induced an increase of the sodium content in vesicles equilibrated with 22Na; the L-arginine uptake did not induce it. These different results suggest that the electrical potential and not the chemical gradient was the major driving force for the L-arginine uptake.
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