49 results on '"Kefi S"'
Search Results
2. Efficacité et tolérance de la toxine botulique dans l’hémispasme facial
- Author
-
Mazlout, H., Kamoun Gargouri, H., Triki, W., Kéfi, S., Brour, J., El Afrit, M.A., Chéour, M., and Kraiem, A.
- Published
- 2013
- Full Text
- View/download PDF
3. Changes in diatom patch-size distribution and degradation in a spatially self-organized intertidal mudflat ecosystem
- Author
-
Weerman, E. J., Van Belzen, J., Rietkerk, M., Temmerman, S., Kéfi, S., Herman, P. M. J., and Van de Koppel, J.
- Published
- 2012
4. Is the patch size distribution of vegetation a suitable indicator of desertification processes? Comment
- Author
-
Kéfi, S., Alados, C. L., Chaves, R. C. G., Pueyo, Y., and Rietkerk, M.
- Published
- 2010
5. Leukemia in Patients with Klinefelter Syndrome: A Report of Two Cases
- Author
-
Bchir, M., Ayed, W., Neji, H. Ben, Kilani, O., Kefi, S., Zarrouk, M., Guermani, H., Hentati, S., Amouri, A., and Meddeb, B.
- Published
- 2016
- Full Text
- View/download PDF
6. Dispersal Strategies and Spatial Organization of Vegetation in Arid Ecosystems
- Author
-
Pueyo, Y., Kéfi, S., Alados, C. L., and Rietkerk, M.
- Published
- 2008
- Full Text
- View/download PDF
7. CASCADE Catastrophic shifts in drylands: how can we prevent ecosystem degradation? Final Publishable Summary : EU - FP7 project Grant Agreement Number 283068
- Author
-
van den Elsen, H.G.M., Hessel, R., Stringer, L.C., Daliakopoulos, I.N., Tsanis, I., Garcia Major, A., de Ruiter, P.C., Bautista, S., Valdecantos, A., Vallejo, R.L., Kefi, S., Schneider, F., Baudena, M., Rietkerk, M., Fleskens, L., Schwilch, G., Juckers, Mara, Geeson, Nicky, Brandt, J., Sietz, D., and de Ita, C.
- Subjects
Soil Physics and Land Management ,Soil, Water and Land Use ,WIMEK ,Life Science ,Bodemfysica en Landbeheer ,PE&RC ,Mathematical and Statistical Methods - Biometris ,Wiskundige en Statistische Methoden - Biometris ,Bodem, Water en Landgebruik - Published
- 2017
8. The ecological forecast horizon, and examples of its uses and determinants
- Author
-
Petchey, O.L., Pontarp, M., Massie, T.M., Kefi, S., Ozgul, A., Weilenmann, M., Palamara, G.M., Altermatt, F., Matthews, B., Levine, J.M., Childs, D.Z., McGill, B.J., Schaepman, M.E., Schmid, B., Spaak, P., Beckerman, A.P., Pennekamp, F., and Pearse, I.S.
- Abstract
Forecasts of ecological dynamics in changing environments are increasingly important, and are available for a plethora of variables, such as species abundance and distribution, community structure and ecosystem processes. There is, however, a general absence of knowledge about how far into the future, or other dimensions (space, temperature, phylogenetic distance), useful ecological forecasts can be made, and about how features of ecological systems relate to these distances. The ecological forecast horizon is the dimensional distance for which useful forecasts can be made. Five case studies illustrate the influence of various sources of uncertainty (e.g. parameter uncertainty, environmental variation, demographic stochasticity and evolution), level of ecological organisation (e.g. population or community), and organismal properties (e.g. body size or number of trophic links) on temporal, spatial and phylogenetic forecast horizons. Insights from these case studies demonstrate that the ecological forecast horizon is a flexible and powerful tool for researching and communicating ecological predictability. It also has potential for motivating and guiding agenda setting for ecological forecasting research and development.
- Published
- 2015
9. Feedbacks between vegetation pattern and resource loss enhance degradation potential in drylands
- Author
-
Mayor AG, Kefi S, Bautista S, Rodriguez F, Rietkerk M., CARTENI', FABRIZIO, Gert-Jan Reichart, Mayor, Ag, Kefi, S, Bautista, S, Rodriguez, F, Carteni', Fabrizio, and Rietkerk, M.
- Abstract
Conceptual frameworks of dryland degradation commonly include ecohydrological feedbacks between landscape spatial organization and resource loss, so that decreasing cover and size of vegetation patches result in higher water and soil losses, which lead to further vegetation loss. However, the impacts of these feedbacks on dryland dynamics in response to external stress have barely been tested. Using a spatially-explicit model, we mimicked feedbacks between vegetation pattern and landscape resource loss by establishing a negative dependence of plant establishment on bare-soil hydrological connectivity. We assessed the impact of various feedback strengths on the response of dryland ecosystems to changing human and climatic pressure. The connectivity-mediated feedbacks decrease the amount of pressure required to cause a critical shift to a degraded state and increase the pressure release needed to achieve the ecosystem recovery. The impact of these feedbacks is markedly non-linear, which is explained by the non-linear increase in bare-soil hydrological connectivity with decreasing vegetation cover. Modelling studies on dryland vegetation dynamics not accounting for the connectivity-mediated feedbacks studied here may underestimate the degradation potential of drylands in response to external stress. Our results also suggest that changes in vegetation pattern and associated hydrological connectivity may be more informative early-warning indicators of dryland degradation than changes in vegetation cover.
- Published
- 2013
10. Leukemia in Patients with Klinefelter Syndrome: A Report of Two Cases
- Author
-
Bchir, M., primary, Ayed, W., additional, Neji, H. Ben, additional, Kilani, O., additional, Kefi, S., additional, Zarrouk, M., additional, Guermani, H., additional, Hentati, S., additional, Amouri, A., additional, and Meddeb, B., additional
- Published
- 2015
- Full Text
- View/download PDF
11. Prongnostic Implication of Cytogenetic Abnomalities for Newly Diagnosed Muliple Myeloma in Young Patients: Tunisian Monocenter Experience
- Author
-
Zarrouk, M., primary, Mejri, A., additional, Mansouri, R., additional, Bechir, M., additional, Beneji, H., additional, Ben Abdennebi, Y., additional, Kacem, K., additional, Kefi, S., additional, Aissaoui, L., additional, Belhajali, Z., additional, Benabid, H., additional, Benlakhel, R., additional, and Meddeb, B., additional
- Published
- 2015
- Full Text
- View/download PDF
12. Early Warning Signals of Ecological Transitions: Methods for Spatial Patterns
- Author
-
Kefi, S., Guttal, V., Brock, W.A., Carpenter, S.R., Ellison, A.M., Livina, V.N., Seekell, D.A., Scheffer, M., van Nes, E.H., Dakos, V., Kefi, S., Guttal, V., Brock, W.A., Carpenter, S.R., Ellison, A.M., Livina, V.N., Seekell, D.A., Scheffer, M., van Nes, E.H., and Dakos, V.
- Abstract
A number of ecosystems can exhibit abrupt shifts between alternative stable states. Because of their important ecological and economic consequences, recent research has focused on devising early warning signals for anticipating such abrupt ecological transitions. In particular, theoretical studies show that changes in spatial characteristics of the system could provide early warnings of approaching transitions. However, the empirical validation of these indicators lag behind their theoretical developments. Here, we summarize a range of currently available spatial early warning signals, suggest potential null models to interpret their trends, and apply them to three simulated spatial data sets of systems undergoing an abrupt transition. In addition to providing a step-by-step methodology for applying these signals to spatial data sets, we propose a statistical toolbox that may be used to help detect approaching transitions in a wide range of spatial data. We hope that our methodology together with the computer codes will stimulate the application and testing of spatial early warning signals on real spatial data.
- Published
- 2014
13. Reading the Signs: Spatial vegetation patterns, arid ecosystems and desertification
- Author
-
Kefi, S., Environmental Sciences, Section Environmental Sciences, de Ruiter, P.C., Rietkerk, Max, and University Utrecht
- Abstract
Human footprint on ecosystems is growing, and ecosystems cope with these changes in different ways. Arid ecosystems are likely to shift abruptly to desert in a sudden and often irreversible manner because of climatic changes or human activities. Such ecosystem shifts can even happen when external changes are gradual, and the conditions under which they occur are still not well understood. For about a third of the world's population who live in arid regions, these shifts are of great importance because they result in a substantial reduction in the biological and economic productivity of these drylands. Models have shown that positive feedbacks between vegetation and its abiotic environment are important mechanisms explaining ecosystem shifts. In harsh habitats, such as arid ecosystems, organisms can indeed alter the physical conditions, making a stressful habitat more hospitable, e.g. by creating shelter or increasing resource availability. For plants, such effects occur locally, below or close to their canopy. Consequently, vegetation tends to grow in clumps which are scattered in an otherwise barren landscape, forming spatial vegetation patterns. This thesis addresses these spatial vegetation patterns: the ecological mechanisms underlying their formation and their potential role as indicators of impending desertification. How do vegetation patterns respond to increasing stress (e.g., increasing aridity), and in particular, do ecosystems have a unique appearance just before a shift? Can specific vegetation patterns help predict when and how ecosystem shifts might occur? We developed mathematical models of arid ecosystems' dynamics including vegetation's ability to improve the local environment, and we used these models to learn how to interpret spatial vegetation patterns. We studied how different positive feedback mechanisms and dispersal strategies affect the type of vegetation patterns that emerges. We analyzed how these patterns respond to changes in the climate and human pressures, such as grazing, at ecological and evolutionary timescales. We found that looking at spatial vegetation patterns gives insight into the ecological mechanism responsible for their formation, the history of the ecosystem, and the ecosystem's "health" (i.e., likelihood to switch to a desert). In particular, we discovered spatial patterns that only occur when an arid ecosystem is about to become a desert, and that the characteristics of these patterns depend on the underlying ecological mechanisms. Further empirical tests are now needed to confirm that spatial vegetation patterns can indeed be used as indicators of imminent desertification. Our findings are appealing because they could represent a significant step toward the development of a widely applicable desertification monitoring system. Since it is fairly straight forward to analyze satellite images, such a monitoring system could help land managers in the near future to map vulnerable regions, and adapt the management of these regions before a potentially disastrous shift occurs.
- Published
- 2008
14. Accumulated gains in a prisoner's dilemma: which game is performed by the players?
- Author
-
Kefi, S., Bonnet, O., Danchin, Etienne, Evolution et Diversité Biologique (EDB), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées
- Subjects
[SDV.EE]Life Sciences [q-bio]/Ecology, environment ,[SDV.BA]Life Sciences [q-bio]/Animal biology ,[SDV.BID]Life Sciences [q-bio]/Biodiversity - Published
- 2007
15. Feedbacks between vegetation pattern and resource loss dramatically decrease ecosystem resilience and restoration potential in a simple dryland model
- Author
-
Mayor, A.G., Kefi, S., Bautista, S., Rodriguez, F., Carteni, F., Rietkerk, M., Mayor, A.G., Kefi, S., Bautista, S., Rodriguez, F., Carteni, F., and Rietkerk, M.
- Published
- 2013
16. Early warning signals also precede non-catastrophic transitions
- Author
-
Kefi, S., Dakos, V., Scheffer, M., Nes, E.H. van, Rietkerk, M., Kefi, S., Dakos, V., Scheffer, M., Nes, E.H. van, and Rietkerk, M.
- Published
- 2013
17. Changes in diatom patch-size distribution and degradation in a spatially self-organized intertidal mudflat ecosystem
- Author
-
Weerman, E.J., Belzen, J. van, Rietkerk, M.G., Temmerman, S., Kefi, S., Herman, P.M.J., Koppel, J. van de, Weerman, E.J., Belzen, J. van, Rietkerk, M.G., Temmerman, S., Kefi, S., Herman, P.M.J., and Koppel, J. van de
- Published
- 2012
18. Methods for Detecting Early Warnings of Critical Transitions in Time Series Illustrated Using Simulated Ecological Data
- Author
-
Dakos, V., Carpenter, S.R., Brock, W.A., Ellison, A.M., Guttal, V., Ives, A.R., Kefi, S., Livina, V., Seekell, D.A., van Nes, E.H., Scheffer, M., Dakos, V., Carpenter, S.R., Brock, W.A., Ellison, A.M., Guttal, V., Ives, A.R., Kefi, S., Livina, V., Seekell, D.A., van Nes, E.H., and Scheffer, M.
- Abstract
Many dynamical systems, including lakes, organisms, ocean circulation patterns, or financial markets, are now thought to have tipping points where critical transitions to a contrasting state can happen. Because critical transitions can occur unexpectedly and are difficult to manage, there is a need for methods that can be used to identify when a critical transition is approaching. Recent theory shows that we can identify the proximity of a system to a critical transition using a variety of so-called ‘early warning signals’, and successful empirical examples suggest a potential for practical applicability. However, while the range of proposed methods for predicting critical transitions is rapidly expanding, opinions on their practical use differ widely, and there is no comparative study that tests the limitations of the different methods to identify approaching critical transitions using time-series data. Here, we summarize a range of currently available early warning methods and apply them to two simulated time series that are typical of systems undergoing a critical transition. In addition to a methodological guide, our work offers a practical toolbox that may be used in a wide range of fields to help detect early warning signals of critical transitions in time series data
- Published
- 2012
19. The ecological and evolutionary implications of merging different types of networks
- Author
-
Fontaine, C., Guimaraes, P.R., Kefi, S., Loeuille, N., Memmott, J., Van der Putten, W.H., Van Veen, F.J.F., Thebault, E., Fontaine, C., Guimaraes, P.R., Kefi, S., Loeuille, N., Memmott, J., Van der Putten, W.H., Van Veen, F.J.F., and Thebault, E.
- Abstract
Interactions among species drive the ecological and evolutionary processes in ecological communities. These interactions are effectively key components of biodiversity. Studies that use a network approach to study the structure and dynamics of communities of interacting species have revealed many patterns and associated processes. Historically these studies were restricted to trophic interactions, although network approaches are now used to study a wide range of interactions, including for example the reproductive mutualisms. However, each interaction type remains studied largely in isolation from others. Merging the various interaction types within a single integrative framework is necessary if we want to further our understanding of the ecological and evolutionary dynamics of communities. Dividing the networks up is a methodological convenience as in the field the networks occur together in space and time and will be linked by shared species. Herein, we outline a conceptual framework for studying networks composed of more than one type of interaction, highlighting key questions and research areas that would benefit from their study., Interactions among species drive the ecological and evolutionary processes in ecological communities. These interactions are effectively key components of biodiversity. Studies that use a network approach to study the structure and dynamics of communities of interacting species have revealed many patterns and associated processes. Historically these studies were restricted to trophic interactions, although network approaches are now used to study a wide range of interactions, including for example the reproductive mutualisms. However, each interaction type remains studied largely in isolation from others. Merging the various interaction types within a single integrative framework is necessary if we want to further our understanding of the ecological and evolutionary dynamics of communities. Dividing the networks up is a methodological convenience as in the field the networks occur together in space and time and will be linked by shared species. Herein, we outline a conceptual framework for studying networks composed of more than one type of interaction, highlighting key questions and research areas that would benefit from their study.
- Published
- 2011
20. Slowing down in spatially patterned ecosystems at the brink of collapse vasilis
- Author
-
Dakos, V., Kefi, S., Rietkerk, M.G., Nes, E.H. van, Scheffer, M., Dakos, V., Kefi, S., Rietkerk, M.G., Nes, E.H. van, and Scheffer, M.
- Published
- 2011
21. Robust scaling in ecosystems and the meltdown of patch size distributions before extinction
- Author
-
Kefi, S., Rietkerk, M.G., Roy, M., Franc, A., Ruiter, P.C. de, Pascual, M., Kefi, S., Rietkerk, M.G., Roy, M., Franc, A., Ruiter, P.C. de, and Pascual, M.
- Published
- 2011
22. The role of reproductive plant traits and biotic interactions in the dynamics of semi-arid plant communities
- Author
-
Pueyo, Y., Kefi, S., Diaz-Sierra, R., Alados, C.L. y, Rietkerk, M.G., Pueyo, Y., Kefi, S., Diaz-Sierra, R., Alados, C.L. y, and Rietkerk, M.G.
- Published
- 2010
23. Reading the Signs: Spatial vegetation patterns, arid ecosystems and desertification
- Author
-
Environmental Sciences, Section Environmental Sciences, de Ruiter, P.C., Rietkerk, Max, Kefi, S., Environmental Sciences, Section Environmental Sciences, de Ruiter, P.C., Rietkerk, Max, and Kefi, S.
- Published
- 2008
24. ChemInform Abstract: Serotoninergic Properties of New Conformationally Restricted Benzamides.
- Author
-
YANG, D., primary, BREMONT, B., additional, SHEN, S., additional, KEFI, S., additional, and LANGLOIS, M., additional
- Published
- 2010
- Full Text
- View/download PDF
25. Occlusion de la veine centrale de la rétine et hypoplasie de l’artère carotide interne : à propos d’un cas
- Author
-
Mazlout, H., primary, Trojet, S., additional, Toumi, A., additional, Kefi, S., additional, Kacem, K. Ben, additional, Nouhaili, H., additional, Dkhillali, R., additional, Afrit, M.A., additional, and Kraiem, A., additional
- Published
- 2010
- Full Text
- View/download PDF
26. The COST system of networking in the field of food and agriculture research
- Author
-
Nedovic, V., primary, Raspor, P., additional, Kefi, S., additional, Williams, J., additional, Obert, W., additional, and Grabert, M., additional
- Published
- 2006
- Full Text
- View/download PDF
27. P156 - Évaluation de l’observance thérapeutique des diabétiques suivis en milieu sanitaire
- Author
-
Ouertani, M., primary, Kefi, S., additional, Alouni, B., additional, Zagdoudi, N., additional, and Mhiri, K., additional
- Published
- 2004
- Full Text
- View/download PDF
28. Hybrid Fuzzy-MutiAgent planning for robust mobile robot motion.
- Author
-
Kefi, S., Kammoun, H.M., Kallel, I., and Alimi, A.M.
- Published
- 2010
- Full Text
- View/download PDF
29. Serotoninergic properties of new conformationally restricted benzamides
- Author
-
Yang, D, primary, Brémont, B, additional, Shen, S, additional, Kefi, S, additional, and Langlois, M, additional
- Published
- 1996
- Full Text
- View/download PDF
30. ChemInform Abstract: Serotoninergic Properties of New Conformationally Restricted Benzamides.
- Author
-
YANG, D., BREMONT, B., SHEN, S., KEFI, S., and LANGLOIS, M.
- Published
- 1996
- Full Text
- View/download PDF
31. Feedbacks between vegetation pattern and resource loss dramatically decrease ecosystem resilience and restoration potential in a simple dryland model
- Author
-
Fabrizio Cartenì, Ángeles G. Mayor, Francisco Rodríguez, Sonia Kéfi, Max Rietkerk, Susana Bautista, Universidad de Alicante. Departamento de Ecología, Universidad de Alicante. Departamento de Matemática Aplicada, Gestión de Ecosistemas y de la Biodiversidad (GEB), Análisis de Datos y Modelización de Procesos en Biología y Geociencias, Copernicus Institute for Sustainable Development, Utrecht University [Utrecht], Centre d'Estudis Ambientals del Mediterrani = Centre for Mediterranean Environmental Studies (CEAM), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, Universidad de Alicante, Università degli studi di Napoli Federico II, Mayor, Ag, Kefi, S, Bautista, S, Rodriguez, F, Carteni', Fabrizio, and Rietkerk, M.
- Subjects
0106 biological sciences ,Resource (biology) ,010504 meteorology & atmospheric sciences ,media_common.quotation_subject ,Geography, Planning and Development ,Resource-leakiness feedbacks ,Vegetation spatial pattern ,010603 evolutionary biology ,01 natural sciences ,Restoration potential ,Natuurwetenschap en innovatiemanagement ,Geneeskunde ,Ecosystem ,ComputingMilieux_MISCELLANEOUS ,Desertification ,Dryland ecosystems ,0105 earth and related environmental sciences ,Nature and Landscape Conservation ,media_common ,Hydrology ,Dryland ecosystem ,Milieukunde ,Ecology ,Resistance (ecology) ,Resilience ,Matemática Aplicada ,Vegetation ,15. Life on land ,Ecología ,Hydrological connectivity ,Arid ,13. Climate action ,Environmental science ,Resource-leakiness feedback ,Psychological resilience ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Landscape ecology - Abstract
Conceptual frameworks of dryland degradation commonly include ecohydrological feedbacks between landscape spatial organization and resource loss, so that decreasing cover and size of vegetation patches result in higher water and soil losses, which lead to further vegetation loss. However, the impacts of these feedbacks on dryland dynamics in response to external stress have barely been tested. Using a spatially-explicit model, we represented feedbacks between vegetation pattern and landscape resource loss by establishing a negative dependence of plant establishment on the connectivity of runoff-source areas (e.g., bare soils). We assessed the impact of various feedback strengths on the response of dryland ecosystems to changing external conditions. In general, for a given external pressure, these connectivity-mediated feedbacks decrease vegetation cover at equilibrium, which indicates a decrease in ecosystem resistance. Along a gradient of gradual increase of environmental pressure (e.g., aridity), the connectivity-mediated feedbacks decrease the amount of pressure required to cause a critical shift to a degraded state (ecosystem resilience). If environmental conditions improve, these feedbacks increase the pressure release needed to achieve the ecosystem recovery (restoration potential). The impact of these feedbacks on dryland response to external stress is markedly non-linear, which relies on the non-linear negative relationship between bare-soil connectivity and vegetation cover. Modelling studies on dryland vegetation dynamics not accounting for the connectivity-mediated feedbacks studied here may overestimate the resistance, resilience and restoration potential of drylands in response to environmental and human pressures. Our results also suggest that changes in vegetation pattern and associated hydrological connectivity may be more informative early-warning indicators of dryland degradation than changes in vegetation cover. This work was supported by the research projects PATTERN (AGCL2008/-05532-C02-01/FOR) and FEEDBACK (CGL2011-30515-C02-01) funded by the Spanish Ministry of Innovation and Science, the EC-funded projects PRACTICE (GA226818) and CASCADE (GA283068), and the project RESINEE funded by the ERA-Net on Complexity. AGM was supported by a postdoctoral contract (APOSTD/2011/005) from the Valencia Regional Government (Generalitat Valenciana), Spain.
- Published
- 2013
- Full Text
- View/download PDF
32. Ballota hirsuta essential oil as a potential multitarget agent against Leishmania parasite: in vitro and in silico studies.
- Author
-
Essid R, Kefi S, Damergi B, Abid G, Fares N, Jallouli S, Tabbene O, and Limam F
- Abstract
In the present study, we assessed the antioxidant and antileishmanial potential from fresh leaves of Ballota (B.) hirsuta essential oil (EO). The GC-MS analysis of B. hirsuta EO revealed that spathulenol and germacrene D were the main components accounting for 26.03% and 19.64% of the total EO, respectively. B. hirsuta EO possesses moderate antioxidant activity, both in neutralizing DPPH radicals and in inhibiting β-carotene bleaching. In addition, it exhibits both high antileishmanial activity and selectivity towards the promastigote and amastigote forms. Specifically, B. hirsuta EO showed an IC
50 value of 20.78 µg/mL and 23.62 µg/mL, against the promastigote and amastigote forms of L. infantum, respectively. It also demonstrated an IC50 value of 22.39 and 25.76 µg/mL, against the promastigote and amastigote forms of L. major, respectively. However, it exhibited moderate cytotoxicity, with a selectivity index below 10. The investigation of the molecular mechanism of action revealed that B. hirsuta EO inhibited only the sterol pathway, including CYP51 gene expression. Additionally, in silico analysis indicated that the main compounds of B. hirsuta EO, germacrene and spathulenol, exhibited excellent affinity energy against Leishmania enzymes trypanothione reductase (TryR) and trypanothione synthase (TryS). This denotes the potential of these compounds as promising agents to control leishmaniasis., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)- Published
- 2024
- Full Text
- View/download PDF
33. Plasma exchange in thrombotic thrombocytopenic purpuras.
- Author
-
Jabr D, Hsasna R, Kefi S, Kharrat R, Ben Neji H, and Ben Lakhal R
- Subjects
- Humans, Retrospective Studies, Female, Male, Middle Aged, Adult, Young Adult, Treatment Outcome, Aged, Recurrence, Plasmapheresis methods, Adolescent, Rituximab therapeutic use, Rituximab administration & dosage, Purpura, Thrombotic Thrombocytopenic therapy, Purpura, Thrombotic Thrombocytopenic diagnosis, Plasma Exchange methods
- Abstract
Introduction: Thrombotic thrombocytopenic purpura (TTP) is a rare but potentially fatal hematological disorder that requires urgent treatment. Once the diagnosis has been made, plasma exchange (PE) must be started immediately and until a response is obtained., Aim: Evaluate PE in terms of responses and complications in the treatment of TTP., Methods: This was a monocentric, descriptive, retrospective study including patients in whom TTP was diagnosed and treated with plasmapheresis in the clinical hematology department at Aziza Othmana Hospital, between January 2010 and December 2020., Results: Our study included 26 patients. PE was initiated within a median of 1 day. The rhythm of exchanges was daily in 22 patients. Twenty PE-related complications were noted, hypocalcemia being the most frequent (30%). CR was achieved in 15 patients after PE alone. Nine patients were refractory, and six received 2nd-line treatment, with CR achieved in five patients. Relapse was noted in six patients (40%). They were treated by PE and only one patient received rituximab. Four patients had a response. The overall response rate was 69% and overall mortality was 30%. OS at 2 years was 68,3% and RFS was 84,4%. Factors associated with the achievement of CR were the fall in LDH at D5 of treatment (p=0,027,OR=0,59 ;IC 95%[0,32-1,08]) and the daily rhythm of PE (p=0,005, OR=0,35; IC 95%[0,14-0,91])., Conclusion: Our results were comparable to those of the literature, but the rate of refractory disease was higher. Rituximab may enhance our results.
- Published
- 2024
- Full Text
- View/download PDF
34. Global Landscape of the Attack of Predatory Journals in Oncology.
- Author
-
El Bairi K, Trapani D, Nidhamalddin SJ, Khan SZ, Chowdhury AR, Lengyel CG, Hussain S, Habeeb BS, Petrillo A, Omar NE, Altuna S, Seid FU, Elfaham E, Seeber A, Roitberg F, Burguete-Torres A, El Kefi S, Hammad N, Mutebi M, Al Jarroudi O, El Kadmiri N, Curigliano G, and Afqir S
- Subjects
- Humans, Cross-Sectional Studies, Open Access Publishing, Periodicals as Topic standards, Surveys and Questionnaires, Peer Review, Research standards, Publishing standards, Medical Oncology
- Abstract
Purpose: Open-access publishing expanded opportunities to give visibility to research results but was accompanied by the proliferation of predatory journals (PJos) that offer expedited publishing but potentially compromise the integrity of research and peer review. To our knowledge, to date, there is no comprehensive global study on the impact of PJos in the field of oncology., Materials and Methods: A 29 question-based cross-sectional survey was developed to explore knowledge and practices of predatory publishing and analyzed using descriptive statistics and binary logistic regression., Results: Four hundred and twenty-six complete responses to the survey were reported. Almost half of the responders reported feeling pressure to publish from supervisors, institutions, and funding and regulatory agencies. The majority of authors were contacted by PJos through email solicitations (67.8%), with fewer using social networks (31%). In total, 13.4% of the responders confirmed past publications on PJo, convinced by fast editorial decision time, low article-processing charges, limited peer review, and for the promise of academic boost in short time. Over half of the participants were not aware of PJo detection tools. We developed a multivariable model to understand the determinants to publish in PJos, showing a significant correlation of practicing oncology in low- and middle-income countries (LMICs) and predatory publishing (odds ratio [OR], 2.02 [95% CI, 1.01 to 4.03]; P = .04). Having previous experience in academic publishing was not protective (OR, 3.81 [95% CI, 1.06 to 13.62]; P = .03). Suggestions for interventions included educational workshops, increasing awareness through social networks, enhanced research funding in LMICs, surveillance by supervisors, and implementation of institutional actions against responsible parties., Conclusion: The prevalence of predatory publishing poses an alarming problem in the field of oncology, globally. Our survey identified actionable risk factors that may contribute to vulnerability to PJos and inform guidance to enhance research capacity broadly.
- Published
- 2024
- Full Text
- View/download PDF
35. Promising Antileishmanial Activity of Micromeria nervosa Essential Oil: In Vitro and In Silico Studies.
- Author
-
Essid R, Kefi S, Damergi B, Abid G, Fares N, Jallouli S, Abid I, Hussein D, Tabbene O, and Limam F
- Subjects
- Antioxidants pharmacology, Antioxidants chemistry, Gas Chromatography-Mass Spectrometry, Sterol 14-Demethylase metabolism, Sterol 14-Demethylase chemistry, Computer Simulation, Leishmania drug effects, Leishmania enzymology, Bicyclic Monoterpenes pharmacology, Bicyclic Monoterpenes chemistry, Oils, Volatile pharmacology, Oils, Volatile chemistry, Antiprotozoal Agents pharmacology, Antiprotozoal Agents chemistry, Molecular Docking Simulation
- Abstract
The present study aimed to evaluate the leishmanicidal potential of the essential oil (EO) of Micromeria ( M. ) nervosa and to investigate its molecular mechanism of action by qPCR. Furthermore, in silicointeraction study of the major M. nervosa EO compounds with the enzyme cytochrome P450 sterol 14α-demethylase (CYP51) was also performed. M. nervosa EO was analyzed by gas chromatography-mass spectrometry (GC-MS). Results showed that α-pinene (26.44%), t -cadinol (26.27%), caryophyllene Oxide (7.73 ± 1.04%), and α-Cadinene (3.79 ± 0.12%) are the major compounds of M. nervosa EO. However, limited antioxidant activity was observed, as this EO was ineffective in neutralizing DPPH free radicals and in inhibiting β-carotene bleaching. Interestingly, it displayed effective leishmanicidal potential against promastigote (IC
50 of 6.79 and 5.25 μg/mL) and amastigote (IC50 of 8.04 and 7.32 μg/mL) forms of leishmania (L.) infantum and L. major , respectively. Molecular mechanism investigation showed that M. nervosa EO displayed potent inhibition on the thiol regulatory pathway. Furthermore, a docking study of the main components of the EO with cytochrome P450 sterol 14α-demethylase (CYP51) enzyme revealed that t -cadinol exhibited the best binding energy values (-7.5 kcal/mol), followed by α-cadinene (-7.3 kcal/mol) and caryophyllene oxide (-7 kcal/mol). These values were notably higher than that of the conventional drug fluconazole showing weaker binding energy (-6.9 kcal/mol). These results suggest that M. nervosa EO could serve as a potent and promising candidate for the development of alternative antileishmanial agent in the treatment of leishmaniasis.- Published
- 2024
- Full Text
- View/download PDF
36. Ethnic and functional differentiation of copy number polymorphisms in Tunisian and HapMap population unveils insights on genome organizational plasticity.
- Author
-
Romdhane L, Kefi S, Mezzi N, Abassi N, Jmel H, Romdhane S, Shan J, Chouchane L, and Abdelhak S
- Subjects
- Humans, HapMap Project, Genotype, Genetics, Population, Polymorphism, Single Nucleotide, DNA Copy Number Variations, Genome, North African People
- Abstract
Admixture mapping has been useful in identifying genetic variations linked to phenotypes, adaptation and diseases. Copy number variations (CNVs) represents genomic structural variants spanning large regions of chromosomes reaching several megabases. In this investigation, the "Canary" algorithm was applied to 102 Tunisian samples and 991 individuals from eleven HapMap III populations to genotype 1279 copy number polymorphisms (CNPs). In this present work, we investigate the Tunisian population structure using the CNP makers previously identified among Tunisian. The study revealed that Sub-Saharan African populations exhibited the highest diversity with the highest proportions of allelic CNPs. Among all the African populations, Tunisia showed the least diversity. Individual ancestry proportions computed using STRUCTURE analysis revealed a major European component among Tunisians with lesser contribution from Sub-Saharan Africa and Asia. Population structure analysis indicated the genetic proximity with Europeans and noticeable distance from the Sub-Saharan African and East Asian clusters. Seven genes harbouring Tunisian high-frequent CNPs were identified known to be associated with 9 Mendelian diseases and/or phenotypes. Functional annotation of genes under selection highlighted a noteworthy enrichment of biological processes to receptor pathway and activity as well as glutathione metabolism. Additionally, pathways of potential concern for health such as drug metabolism, infectious diseases and cancers exhibited significant enrichment. The distinctive genetic makeup of the Tunisians might have been influenced by various factors including natural selection and genetic drift, resulting in the development of distinct genetic variations playing roles in specific biological processes. Our research provides a justification for focusing on the exclusive genome organization of this population and uncovers previously overlooked elements of the genome., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
37. Opportunities, challenges, and future directions for simulation modeling the effects of structural racism on cancer mortality in the United States: a scoping review.
- Author
-
Jayasekera J, El Kefi S, Fernandez JR, Wojcik KM, Woo JMP, Ezeani A, Ish JL, Bhattacharya M, Ogunsina K, Chang CJ, Cohen CM, Ponce S, Kamil D, Zhang J, Le R, Ramanathan AL, Butera G, Chapman C, Grant SJ, Lewis-Thames MW, Dash C, Bethea TN, and Forde AT
- Subjects
- Humans, Black or African American, Health Status Disparities, United States epidemiology, Hispanic or Latino, White, Neoplasms mortality, Neoplasms therapy, Systemic Racism
- Abstract
Purpose: Structural racism could contribute to racial and ethnic disparities in cancer mortality via its broad effects on housing, economic opportunities, and health care. However, there has been limited focus on incorporating structural racism into simulation models designed to identify practice and policy strategies to support health equity. We reviewed studies evaluating structural racism and cancer mortality disparities to highlight opportunities, challenges, and future directions to capture this broad concept in simulation modeling research., Methods: We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Scoping Review Extension guidelines. Articles published between 2018 and 2023 were searched including terms related to race, ethnicity, cancer-specific and all-cause mortality, and structural racism. We included studies evaluating the effects of structural racism on racial and ethnic disparities in cancer mortality in the United States., Results: A total of 8345 articles were identified, and 183 articles were included. Studies used different measures, data sources, and methods. For example, in 20 studies, racial residential segregation, one component of structural racism, was measured by indices of dissimilarity, concentration at the extremes, redlining, or isolation. Data sources included cancer registries, claims, or institutional data linked to area-level metrics from the US census or historical mortgage data. Segregation was associated with worse survival. Nine studies were location specific, and the segregation measures were developed for Black, Hispanic, and White residents., Conclusions: A range of measures and data sources are available to capture the effects of structural racism. We provide a set of recommendations for best practices for modelers to consider when incorporating the effects of structural racism into simulation models., (Published by Oxford University Press 2023.)
- Published
- 2023
- Full Text
- View/download PDF
38. ["Assure" program, to improve the management of emergency situations in Ehpad].
- Author
-
Cloppet Fontaine A, Boudier C, Clément R, Guillaud C, Leduc B, Bonneaux C, Kefi S, Dufour I, Bongrand E, and Li Peng C
- Subjects
- Humans, Aged, Caregivers, France, Nursing Homes, Emergency Medical Services
- Abstract
The Assure approach (improvement of emergency care) is a project designed to improve emergency care for the 63,000 residents of homes for the dependent elderly (Ehpad) in the Ile-de-France region. By reinforcing the skills of caregivers in emergency situations and facilitating collaboration between care providers, the Assure approach is mobilizing, alongside all the Ehpad in the Ile-de-France region over a period of two years, the emergency medical assistance services, emergency physicians, mobile geriatric teams and nursing and care assistant training institutes., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
39. Antioxidant, antibacterial, and antileishmanial potential of Micromeria nervosa extracts and molecular mechanism of action of the bioactive compound.
- Author
-
Kefi S, Essid R, Papetti A, Abid G, Bouslama L, Aouani E, Tabbene O, and Limam F
- Subjects
- Antioxidants pharmacology, Antioxidants analysis, Ether, Plant Extracts pharmacology, Plant Extracts chemistry, Anti-Bacterial Agents pharmacology, Staphylococcus aureus, Ursolic Acid, Methicillin-Resistant Staphylococcus aureus, Antiprotozoal Agents pharmacology, Anti-Infective Agents pharmacology, Lamiaceae
- Abstract
Aims: This study aimed to determine the antibacterial and antileishmanial potential of Micromeria nervosa extracts. The identification of the antileishmanial compound and the study of its molecular mechanism of action have also been undertaken., Methods and Results: Ethanol extract showed high polyphenol content and diethyl ether extract exhibited high DPPH scavenging and low beta-carotene bleaching activity (IC50 = 13.04 ± 0.99 and 200.18 ± 3.32 μg mL-1, respectively). However, diethyl ether extract displayed high antibacterial activity against Gram-positive strains including methicillin-resistant Staphylococcus aureus (MIC = 31.25 μg mL-1), Staph. aureus ATCC6538 (MIC = 62.5 μg mL-1), and Listeria monocytogenes ATCC 19115 (MIC = 125 μg mL-1), as well as high antileishmanial activity against the promastigote forms of L. infantum and L. major (IC50 = 11.45 and 14.53 μg mL-1, respectively). The active compound was purified using bioassay-guided fractionation and thin layer chromatography, and identified as ursolic acid using high-performance liquid chromatography coupled with a photodiode array and mass spectrometry. The purified compound was strongly inhibitory against the promastigote and amastigote forms of L. infantum and L. major (IC50 = 5.87 and 6.95 μg mL-1 versus 9.56 and 10. 68 μg mL-1, respectively) without overt cytotoxicity against Raw 264.7 macrophage cells (SI = 13.53 and 11.43, respectively). The commercial compound (ursolic acid) showed similar activity against amastigotes and promastigotes forms of L. infantum and L. major. Moreover, its molecular mode of action against leishmaniasis seems to involve the expression of the ODC and SPS genes involved in thiol pathway., Conclusion: Extracts of M. nervosa can be considered as a potential alternative to antimicrobial and antileishmanial drugs., (© The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International.)
- Published
- 2023
- Full Text
- View/download PDF
40. Multiple myeloma with Auer-rod-like inclusions.
- Author
-
Fekih Salem S, Borgi WE, BenLakhal F, Kefi S, Meddeb M, Meddeb B, and Gouider E
- Subjects
- Humans, Inclusion Bodies, Plasma Cells, Multiple Myeloma diagnosis
- Published
- 2021
- Full Text
- View/download PDF
41. Hydromethanolic root and aerial part extracts from Echium arenarium Guss suppress proliferation and induce apoptosis of multiple myeloma cells through mitochondrial pathway.
- Author
-
Limam I, Ben Aissa-Fennira F, Essid R, Chahbi A, Kefi S, Mkadmini K, Elkahoui S, and Abdelkarim M
- Subjects
- Apoptosis, Cell Line, Tumor, Cell Proliferation, Humans, Mitochondria, Plant Components, Aerial, Plant Extracts, Echium, Multiple Myeloma drug therapy
- Abstract
Echium arenarium Guss is a Mediterranean plant traditionally used in healing skin wound and it was reported exhibiting potent antioxidant, antibacterial, and antiparasitic activities. However, antitumoral activities of this plant have not yet been explored. Here we investigated for the first time, root (EARE) and aerial part (EAAPE) extracts of E. arenarium Guss to examine cytotoxicity and apoptosis activation pathway on U266 human multiple myeloma (MM) cell line. We demonstrated that EARE and EAAPE decreased U266 cell viability in a dose dependent manner. Based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, EARE was significantly two times more efficient (IC50 value 41 μg/ml) than EAAPE (IC50 value 82 μg/ml) considering 48 h of treatment. Furthermore, after 24 h of exposure to 100 μg/ml of EARE or EAAPE, cell cycle showed remarkable increase in sub-G1 population and a decrease of U266 cells proportion in G1 phase. In addition, EARE increased cell percentage in S phase. Moreover, analysis revealed that EAAPE or EARE induced apoptosis of U266 cells after 24 h of treatment. Interestingly, depolarization of mitochondrial membrane potential and activation of caspase 3/7 were demonstrated in treated U266 cells. Phytochemical analysis of E. arenarium extracts showed that EARE exhibited the highest content of total phenolic content. Interestingly, six phenolic compounds were identified. Myricitrin was the major compound in EARE, followed by luteolin 7-O-glucoside, resorcinol, polydatin, Trans-hydroxycinnamic acid, and hyperoside. These findings proved that an intrinsic mitochondria-mediated apoptosis pathway probably mediated the apoptotic effects of E. arenarium Guss extracts on U266 cells, and this will suggest several action plans to treat MM., (© 2021 Wiley Periodicals LLC.)
- Published
- 2021
- Full Text
- View/download PDF
42. Phytochemical investigation and biological activities of Echium arenarium (Guss) extracts.
- Author
-
Kefi S, Essid R, Mkadmini K, Kefi A, Mahjoub Haddada F, Tabbene O, and Limam F
- Subjects
- Animals, Anti-Bacterial Agents pharmacology, Anti-Infective Agents chemistry, Antioxidants analysis, Antioxidants pharmacology, Biphenyl Compounds, Chromatography, High Pressure Liquid, Flavones analysis, Flavonoids analysis, Glucosides analysis, Gram-Negative Bacteria drug effects, Gram-Positive Bacteria drug effects, Leishmania infantum drug effects, Leishmania major drug effects, Mice, Microbial Sensitivity Tests, Phenols analysis, Phenols pharmacology, Picrates, RAW 264.7 Cells drug effects, beta Carotene, Anti-Infective Agents pharmacology, Echium chemistry, Phytochemicals chemistry, Phytochemicals pharmacology, Plant Extracts chemistry, Plant Extracts pharmacology
- Abstract
The present work was developed to evaluate the in vitro antioxidant, antibacterial, antileishmanial and cytotoxic activities of Echium arenarium (Guss) extracts, and to analyze their phytochemical composition. The highest content of total phenolic compounds was obtained in the ethyl acetate extract which showed the best DPPH scavenging activity and β-carotene bleaching inhibition (IC
50 = 1.1 and 9.94 μg/mL respectively). It also exhibited the highest antibacterial activity against Gram-positive bacteria (L. monocytogenes; S. aureus; MRSA, E. faecalis and B. cereus) and antileishmanial activity against L. major (IC50 = 13.91 ± 0.43 μg/mL) and L. infantum (IC50 = 9.91 ± 0.15 μg/mL). Moreover, the active extract exhibited potent antiamastigote activity (IC50 = 22.48 ± 0.14 μg/mL and 18.59 ± 0.09 μg/mL against L. major and L. infantum respectively). Cytotoxicity studies revealed low toxicity against Raw 264.7 macrophage cell line (IC50 = 145.80 ± 0.84 μg/mL, SI < 10). Luteolin-7-O-glucoside was identified as the major flavonoid component by RP-HPLC analysis. In conclusion, Echium arenarium (Guss) extract was characterized by a wide range of biological activities and could be used as a potential natural anti-infectious drug., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
43. Effects of trophic similarity on community composition.
- Author
-
Morlon H, Kefi S, and Martinez ND
- Subjects
- Animals, Lakes, New York, Food Chain
- Abstract
Understanding how ecological processes determine patterns among species coexisting within ecosystems is central to ecology. Here, we explore relationships between species' local coexistence and their trophic niches in terms of their feeding relationships both as consumers and as resources. We build on recent concepts and methods from community phylogenetics to develop a framework for analysing mechanisms responsible for community composition using trophic similarity among species and null models of community assembly. We apply this framework to 50 food webs found in 50 Adirondack lakes and find that species composition in these communities appears to be driven by both bottom-up effects by which the presence of prey species selects for predators of those prey, and top-down effects by which prey more tolerant of predation out-compete less tolerant prey of the same predators. This approach to community food webs is broadly applicable and shows how species interaction networks can inform an increasingly large array of theory central to community ecology., (© 2014 John Wiley & Sons Ltd/CNRS.)
- Published
- 2014
- Full Text
- View/download PDF
44. Ripening stage and extraction method effects on physical properties, polyphenol composition and antioxidant activities of cumin (Cuminum cyminum L.) seeds.
- Author
-
Rebey IB, Kefi S, Bourgou S, Ouerghemmi I, Ksouri R, Tounsi MS, and Marzouk B
- Subjects
- Antioxidants analysis, Biphenyl Compounds metabolism, Cinnamates analysis, Cinnamates pharmacology, Coumaric Acids analysis, Coumaric Acids pharmacology, Depsides analysis, Depsides pharmacology, Flavonoids analysis, Flavonoids pharmacology, Humans, Phenols analysis, Phenols pharmacology, Picrates metabolism, Plant Extracts analysis, Polyphenols analysis, Propionates, Tannins analysis, Water analysis, Rosmarinic Acid, Antioxidants pharmacology, Cuminum chemistry, Plant Extracts pharmacology, Polyphenols pharmacology, Seeds chemistry, Spices analysis
- Abstract
The effects of two extraction methods, used at three ripening stages on the total polyphenol contents and the antioxidant activities of Cumin (Cuminum cyminum L.) seed extracts were studied. The ripening stage effect on some physical properties of cumin seed was significant. The increase of dry matter (from 10.3 to 87.5%) during ripeness was correlated negatively with that of moisture content (from 89.7 to 12.5%). Besides results showed that the full ripe seeds were richer on polyphenols and condensed tannin than unripe ones, and consequently exhibited higher antioxidant activities. However, the unripe seeds had a higher total flavonoid content compared to those of half ripe and full ripe ones. The comparison of two extraction methods showed that soxhlet extracts contained the greatest amount of polyphenols and flavonoids, while maceration samples exhibited higher antiradical and bleaching power assay. Total phenolic contents and IC50 (concentration required to cause a 50% DPPH inhibition) values in cumin seed during their maturation allowed to conclude that antioxidant activity does not depend only on the high content of total phenolics but also on the phenolic composition. A total of 19 phenolic compounds were successfully identified by HPLC analysis during the ripening of cumin seeds. Rosmarinic acid was the major phenolic acid for the unripe seeds. Furthermore, half ripe and full ripe seeds were dominated by p-coumaric acid. These compounds might be considered as interesting bioactive natural substances that may be used in several fields, such as nutraceuticals, cosmetics and agro-food industry.
- Published
- 2014
- Full Text
- View/download PDF
45. Evaluation of antibacterial, antifungal, and antioxidant activities of safflower natural dyes during flowering.
- Author
-
Salem N, Msaada K, Elkahoui S, Mangano G, Azaeiz S, Ben Slimen I, Kefi S, Pintore G, Limam F, and Marzouk B
- Subjects
- Anti-Bacterial Agents chemistry, Antifungal Agents chemistry, Antioxidants chemistry, Bacteria drug effects, Carthamus chemistry, Chalcone administration & dosage, Chalcone analogs & derivatives, Chalcone chemistry, Cyclohexanones administration & dosage, Cyclohexanones chemistry, Flowers chemistry, Free Radical Scavengers administration & dosage, Free Radical Scavengers chemistry, Fungi drug effects, Glucosides administration & dosage, Glucosides chemistry, Plant Extracts chemistry, Anti-Bacterial Agents administration & dosage, Antifungal Agents administration & dosage, Antioxidants administration & dosage, Plant Extracts administration & dosage
- Abstract
Two Carthamus tinctorius varieties (Jawhara and 104) were studied in order to investigate their natural dyes contents and biological activities. Obtained results showed that quinochalcone contents and antioxidant activities varied considerably as function of flowering stages. So flowers at fructification stage contained the highest carthamin content with the strongest antioxidant capacity with all assays (FRAP, DPPH, and chelating power methods). In parallel, we showed a decrease in the content of precarthamin. The quantitative variation of these molecules could be due to colour change of C. tinctorius flowers. Correlation analysis indicated that the ABTS method showed the highest correlation coefficients with carthamin and precarthamin contents, that is, 0.886 and 0.973, respectively. Concerning the regional effect, the contents of precarthamin and carthamin varied significantly (P < 0.05) at studied regions with the optimum production given by samples of Beja (902.41 μg/g DW and 42.05 μg/g DW, respectively, at flowering stage). During flowering, the antimicrobial activity of these two natural dyes increased where the maximum inhibitory effect mentioned with carthamin mainly against E. coli (iz = 25.89 mm) at fructification stage. Therefore, the increased frequency of resistance to commonly used antibiotics leads to the search for new effective natural drugs at food and pharmaceutical industries.
- Published
- 2014
- Full Text
- View/download PDF
46. [Central retinal vein occlusion and internal carotid artery hypoplasia: a case report].
- Author
-
Mazlout H, Trojet S, Toumi A, Kefi S, Ben Kacem K, Nouhaili H, Dkhillali R, Afrit MA, and Kraiem A
- Subjects
- Adult, Female, Humans, Carotid Artery, Internal abnormalities, Retinal Artery Occlusion complications
- Abstract
Introduction: Retinal vein occlusion is usually encountered in the elderly and is often associated with systemic vascular disease. It is rarer in young subjects and requires a serious etiological search to best adapt the treatment., Observation: We report the case of a central retinal vein occlusion (CRVO) in a 26-year-old patient who had no pathological history, discovered at a sudden decline of vision in the right eye, reduced to light perception. Fundus examination and retinal angiography showed an edematous CRVO. Radiologic imaging revealed a narrowing of the right carotid canal, probably congenital, and a reduction in the size of the right common carotid artery and internal carotid artery. Progression was favorable without treatment, and visual acuity improved to 8/10., Conclusion: The etiological investigation in retinal vein occlusion in young people must be exhaustive. The visual prognosis is variable and may depend on the etiology., (Copyright (c) 2009 Elsevier Masson SAS. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
47. Vegetation pattern shift as a result of rising atmospheric CO2 in arid ecosystems.
- Author
-
Kefi S, Rietkerk M, and Katul GG
- Subjects
- Biomass, Temperature, Atmosphere, Carbon Dioxide metabolism, Ecosystem, Plants metabolism
- Abstract
Arid ecosystems are expected to be among the ecosystems most sensitive to climate change. Here, we explore via model calculations how regular vegetation patterns, widely observed in arid ecosystems, respond to projected climatic shifts as provided by general circulation model output. In our model, the photosynthesis and respiration terms are explicitly linked to physiological attributes of the plants and are forced with the primary climatic drivers: atmospheric CO(2), air temperature, and precipitation. Under future climate scenarios, our simulations show that the system's fate depends on whether the enhancements to photosynthesis due to elevated atmospheric CO(2) outweigh the increases in respiration due to higher air temperatures and the increases in water stress due to lower rainfall. A scalar measure is proposed to quantify this balance between the changes in the three climate drivers. Our model results suggest that knowing how the three primary climate drivers are evolving may provide hints as to whether the ecosystem is approaching desertification.
- Published
- 2008
- Full Text
- View/download PDF
48. [Contribution of immunohistochemical detection of human herpesvirus-8 latent nuclear antigen-1 in the diagnosis of Kaposi disease].
- Author
-
Rammeh-Rommani S, Zermani R, Kefi S, Ferchichi L, Zouari B, Fezaa B, Kammoun MR, and Ben Jilani SB
- Subjects
- Herpesvirus 8, Human immunology, Humans, Immunohistochemistry, Retrospective Studies, Xeroderma Pigmentosum metabolism, Xeroderma Pigmentosum virology, Nuclear Proteins metabolism, Phosphoproteins metabolism, Xeroderma Pigmentosum diagnosis
- Abstract
Aims: To study the immunohistochemical expression of HHV8 in Kaposi's lesions and in other vascular lesions and to determine the utility of this technique in differentiating between Kaposi's disease (KD) and other vascular lesions., Methods: Fixed, paraffin-embedded tissue sections from 25 cases of KD, 9 cases of hemangioma, 2 cases of angiolymphoid hyperplasia with eosinophilia and 9 cases of angiosarcoma were examined immunohistochemically using the monoclonal antibody monoclonal LNA 53 (ABI). Strong, nuclear and granular staining in at least a cell was considered as a positive result., Results: Sixteen cases of KD showed positive staining, whereas all cases of hemangioma, angiolymphoid hyperplasia with eosinophilia and angiosarcoma were negative for this antigen, Conclusion: Immunohistochemical detection of the human herpesvirus-8 latent nuclear antigen-1 is a useful for differentiating between KD and other vascular lesions.
- Published
- 2007
49. Benzamides derived from 1,2-diaminocyclopropane as novel ligands for human D2 and D3 dopamine receptors.
- Author
-
Yang D, Kefi S, Audinot V, Millan MJ, and Langlois M
- Subjects
- Animals, Benzamides chemistry, CHO Cells, Cattle, Cricetinae, Humans, Magnetic Resonance Spectroscopy, Radioligand Assay, Rats, Receptors, Dopamine D3, Benzamides metabolism, Cyclopropanes chemistry, Receptors, Dopamine D2 metabolism
- Abstract
Benzamides (3a-f) derived from 4-amino-5-chloro-2-methoxybenzoic acid and either cis or trans 1,2-diaminocyclopropane were synthesised and were evaluated in binding assays employing, bovine striatal D2 receptors, recombinant human hD2 and hD3 receptors expressed in CHO cells and rat, cortical 5-HT3 and striatal 5-HT4 receptors. The cis and trans isomers of the derivatives were isolated and characterised. The results demonstrated the superiority of the cis conformers over the trans conformers in dopamine receptor binding assays (Ki hD2 = 13.4 and 6.9 nM and Ki hD3 = 17.7 and 4.5 nM for the cis-3b and cis-3f compounds, respectively; Ki hD2 = 816 and >l000 nM and Ki hD3 = 469 and >1000 nM for the corresponding trans-3b and trans-3f compounds respectively). The cis compounds are folded: the benzamide group and the basic nitrogen atom were in a syn relationship. Compound 3f can be superimposed with a conformation of the tropane derivative, BRL 25594, having the benzyl group in an axial position to give a suitable fit, indicating that both compounds may have a common binding site in the dopamine receptor.
- Published
- 2000
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.