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1.
Data Brief ; 39: 107523, 2021 Dec.
Article de Anglais | MEDLINE | ID: mdl-34805457

RÉSUMÉ

This article summarizes synchrotron wide-angle x-ray diffraction (WAXD) patterns, polarized attenuated Fourier transform infrared spectroscopy (ATR-FTIR) data and differential scanning calorimetry (DSC) data of differently stress-annealed poly(3-hydroxybutyrate) (P3HB) fibers. Additionally, in-situ polarized ATR-FTIR data has been measured under tensile drawing of pre-annealed P3HB fibers under low annealing stress. Modifications to the ATR-FTIR setup and sample holders for performing measurements on P3HB fibers are explained in the experimental section. For more information see 'Reversible mesophase in stress-annealed poly(3-hydroxybutyrate) fibers: A synchrotron x-ray and polarized ATR-FTIR study' [1].

2.
Data Brief ; 38: 107416, 2021 Oct.
Article de Anglais | MEDLINE | ID: mdl-34632014

RÉSUMÉ

This data in brief article summarizes structural data obtained from monocomponent melt-spun and offline drawn poly(ethylene terephthalate) (PET) monofilaments, as well as from melt-spun bicomponent core-sheath PET-polyamide 6 (PA6) filaments. The diameters of the single filaments range from 27 µm to 79 µm. Presented analysis techniques and results thereof are (i) Raman mapping of filament cross-sections: 2D maps of peak positions, widths, peak area ratios; (ii) attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR): ATR-FTIR spectra and extraction of surface crystallinity; (iii) wide-angle x-ray diffraction (WAXD): WAXD patterns and extraction of average crystallinity; (iv) small-angle x-ray scattering (SAXS): SAXS patterns and determined crystallite sizes and long-spacings; (v) differential scanning calorimetry (DSC): thermograms and extracted average crystallinity as well as thermal properties; (vi) atomic force microscopy (AFM): AFM image of the surface of an embedded fiber cross-section. For more information, see the publication by E. Perret et al. 'High-resolution 2D Raman mapping of mono- and bicomponent filament cross-sections' [1].

3.
Data Brief ; 32: 106223, 2020 Oct.
Article de Anglais | MEDLINE | ID: mdl-32939379

RÉSUMÉ

Rheological and thermal properties of the poly(ɛ-caprolactone) (PCL) polymer are presented in Section 1.1. Section 1.2 summarizes results of melt-spun PCL filaments. Specifically, we show the necking point stabilization during high-speed online drawing in Section 1.2.1, filament morphology in Section 1.2.2, wide-angle X-ray diffraction (WAXD) fitting results in Section 1.2.3, WAXD patterns of aged fibers in Section 1.2.4, crystallinity analysis in Section 1.2.5 and small-angle X-ray scattering (SAXS) analysis results in Section 1.2.6. Details about the materials, experimental and analytical methods are given in Section 2. Of particular interest may be the simulation and fitting procedures of 2D WAXD patterns, which are summarized in Section 2.7.2. For more information see the publication by Selli et al. 'Mesophase in melt-spun poly(ɛ-caprolactone) filaments: structure-mechanical property relationship' [1].

4.
J Phys Condens Matter ; 29(49): 495601, 2017 12 13.
Article de Anglais | MEDLINE | ID: mdl-29134950

RÉSUMÉ

We studied the structural, magnetic and electronic properties of [Formula: see text] (SFO) thin films and [Formula: see text]/[Formula: see text] [Formula: see text]MnO3 (LCMO) superlattices that have been grown with pulsed laser deposition (PLD) on [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] (LSAT) substrates. X-ray reflectometry and scanning transmission electron microscopy (STEM) confirm the high structural quality of the films and flat and atomically sharp interfaces of the superlattices. The STEM data also reveal a difference in the interfacial layer stacking with a SrO layer at the LCMO/SFO and a LaO layer at the SFO/LCMO interfaces along the PLD growth direction. The x-ray diffraction (XRD) data suggest that the as grown SFO films and SFO/LCMO superlattices have an oxygen-deficient [Formula: see text] structure with I4/ mmm space group symmetry ([Formula: see text]). Subsequent ozone annealed SFO films are consistent with an almost oxygen stoichiometric structure ([Formula: see text]). The electronic and magnetic properties of these SFO films are similar to the ones of corresponding single crystals. In particular, the as grown [Formula: see text] films are insulating whereas the ozone annealed films are metallic. The magneto-resistance effects of the as grown SFO films have a similar magnitude as in the single crystals, but extend over a much wider temperature range. Last but not least, for the SFO/LCMO superlattices we observe a rather large exchange bias effect that varies as a function of the cooling field.

5.
Rev Sci Instrum ; 84(2): 025111, 2013 Feb.
Article de Anglais | MEDLINE | ID: mdl-23464255

RÉSUMÉ

In the growing field of in operando and in situ X-ray experiments, there exists a large disparity in the types of environments and equipment to control them. This situation makes it challenging to conduct multiple experiments with a single mechanical interface to the diffractometer. Here, we describe the design and implementation of a modular instrument mounting system that can be installed on a standard six-circle diffractometer (e.g., 5021 Huber GmbH). This new system allows for the rapid changeover of different chambers and sample heaters and permits accurate sample positioning (x, y, z, and azimuthal rotation) without rigid coupling to the chamber body. Isolation of the sample motion from the chamber enclosure is accomplished through a combination of custom rotary seals and bellows. Control of the pressure and temperature has been demonstrated in the ranges of 10(-6)-10(3) Torr and 25°C-900°C, respectively. We have utilized the system with several different modular instruments. As an example, we provide in situ sputtering results, where the growth dynamics of epitaxial LaGaO3 thin films on (001) SrTiO3 substrates were investigated.

6.
Qual Life Res ; 22(3): 509-20, 2013 Apr.
Article de Anglais | MEDLINE | ID: mdl-22476573

RÉSUMÉ

PURPOSE: To cross-culturally adapt a French version of the LEIPAD, a self-administered questionnaire assessing the health-related quality of life (HRQoL) in adults aged 65 years and over living at home, and to evaluate its psychometric properties. METHODS: After having translated LEIPAD in accordance with guidelines, we studied psychometric properties: reliability and construct validity-factor analysis, relationships between items and scales, internal consistency, concurrent validity with the Medical Outcome Study Short-Form 36 and known-groups validity. RESULTS: The results obtained in a sample of 195 elderly from the general population showed very good acceptability, with response rates superior to 93 %. Exploratory factor analysis extracted eight factors providing a multidimensionality structure with five misclassifications of items in the seven theoretical scales. Good internal consistency (Cronbach's alpha ranging from 0.73 and 0.86) and strong test-retest reliability (ICCs higher than 0.80 for six scales and 0.70 for one) were demonstrated. Concurrent validity with the SF-36 showed small to strong expected correlations. CONCLUSION: This first evaluation of the French version of LEIPAD's psychometric properties provides evidence in construct validity and reliability. It would allow HRQoL assessment in clinical and common practice, and investigators would be able to take part in national and international research projects.


Sujet(s)
État de santé , , Psychométrie/instrumentation , Qualité de vie , Enquêtes et questionnaires , Sujet âgé , Sujet âgé de 80 ans ou plus , Comparaison interculturelle , Culture (sociologie) , Analyse statistique factorielle , Femelle , Humains , Langage , Mâle , Psychométrie/statistiques et données numériques , Reproductibilité des résultats , Facteurs socioéconomiques , Traduction
7.
Phys Rev Lett ; 108(3): 037802, 2012 Jan 20.
Article de Anglais | MEDLINE | ID: mdl-22400786

RÉSUMÉ

We address the fundamental question: how are pair correlations and structure factors of hard-sphere fluids affected by confinement between hard planar walls at close distance? For this purpose, we combine x-ray scattering from colloid-filled nanofluidic channel arrays and first-principles inhomogeneous liquid-state theory within the anisotropic Percus-Yevick approximation. The experimental and theoretical data are in remarkable agreement at the pair-correlation level, providing the first quantitative experimental verification of the theoretically predicted confinement-induced anisotropy of the pair-correlation functions for the fluid. The description of confined fluids at this level provides, in the general case, important insights into the mechanisms of particle-particle interactions in dense fluids under confinement.

8.
Rev Laryngol Otol Rhinol (Bord) ; 131(1): 65-7, 2010.
Article de Français | MEDLINE | ID: mdl-21086661

RÉSUMÉ

PURPOSE: To evaluate a population of dysphonic treated in rehabilitation by comparing the VHI score and GRB scale. MATERIALS AND METHODS: 300 questionnaires were completed, only 42 cases were matched before and after 15 rehabilitation sessions; that is 84 questionnaires. Patients were divided into two groups: group 1 (impaired mobility of the vocal cords), group 2 (benign mucosal lesions). All patients completed a VHI questionnaire, a questionnaire evaluating subjective voice abuse (SSVS), a GRB score. The two tests were correlated to the diagnosis of voice pathology but also used for follow up after voice therapy. The tests used for statistical studies were: comparison by pathology by unpaired series tests (theoretical deviation=0); mean tests, Wilcoxon type. RESULTS: Patients were more handicapped by impaired mobility of the vocal cord than by a nodule or a cyst. The patients' vocal handicap (VHI) was significantly lower after 15 therapy sessions, in all of its components. The perceptual evaluation GRB is also significantly better for these patients after 15 therapy sessions. We could not demonstrate a favorable evolution, that is a diminution of the SSVS before and after 15 sessions. CONCLUSION: The efficacy of speech therapy for certain vocal cord pathologies has been demonstrated both in respect of the Vocal Handicap felt by the patient as well as the Hirano scale.


Sujet(s)
Dysphonie/diagnostic , Dysphonie/psychologie , Humains , Phonétique , Orthophonie , Statistique non paramétrique , Enquêtes et questionnaires
9.
Encephale ; 36 Suppl 2: D105-18, 2010 Jun.
Article de Français | MEDLINE | ID: mdl-20513453

RÉSUMÉ

INTRODUCTION: During the past 15 years, therapeutic effects of repetitive Transcranial Magnetic Stimulation (rTMS) have been studied in psychiatric diseases, particularly in the treatment of depressive disorders. There are more and more data suggesting its efficacy in the treatment of depression in older patients. Thus, the authors found it useful to conduct an up-to-date review of studies that examined the efficacy and safety of rTMS to treat depressive disorders in the aged. METHOD: After an exhaustive consultation of databases (Medline/PubMed and the Avery-George-Holtzheimer Database of rTMS Depression Studies), supplemented by a manual research, the authors retained studies evaluating the therapeutic efficacy of rTMS on depressive disorders in the aged. RESULTS: Fifteen studies were retained. Four open studies using high frequency rTMS, applied to the left dorsolateral prefrontal cortex (DLPFC), demonstrated a decrease in the mean Hamilton Depression Rating Scale (HDRS) scores; however, only a quarter of the aged patients studied experienced a significant remission of depression. Five parallel arm double-blind versus placebo studies concluded in contradicting results: two studies confirmed a significantly greater efficacy of rTMS compared to placebo, whereas three studies did not; but the sham procedure (positioning coil at 90 degrees from the scalp) was disputable in most studies. One study concluded in therapeutic efficacy by inhibiting the right DLPFC. Three controlled parallel arm studies compared rTMS and electroconvulsive-therapy (ECT); one study concluded in greater efficacy of ECT at end of treatment, but the number of ECT treatments depended on the patients' response, whereas a 15-day course of rTMS was systematically administered; additionally HDRS scores were similar in two groups of patients (rTMS and ECT) at 6 months. Lastly, three studies focused on aged patients with cerebrovascular disease. They showed the efficacy of rTMS, although older age and smaller frontal gray mater volumes were associated with a poorer response to rTMS. DISCUSSION: Thus, although some studies concluded contradicting results, literature data globally sustain an efficacy of rTMS for depression in the elderly. Several parameters might be associated with greater antidepressant efficacy (higher intensity pulses of rTMS of the left DLPFC; higher number of stimulations or higher number of rTMS sessions). Poorer responsiveness to rTMS may be related to several patients' factors including older age and smaller frontal gray matter volumes; lesions of the white matter pathways connecting the left DLPFC and the left anterior cingulate cortex might explain a poor response to rTMS. Literature data globally confirm that rTMS is safe and does not produce cognitive deficits, even among highly vulnerable patients with clinical evidence of cerebrovascular disease. CONCLUSION: Many questions remain concerning the optimal stimulation parameters, administration protocol, and privileged indications. Thus, the next rTMS studies should be carefully designed to clarify these questions.


Sujet(s)
Trouble dépressif majeur/thérapie , Stimulation magnétique transcrânienne , Sujet âgé , Sujet âgé de 80 ans ou plus , Essais cliniques contrôlés comme sujet , Trouble dépressif majeur/diagnostic , Trouble dépressif majeur/physiopathologie , Trouble dépressif majeur/psychologie , Dominance cérébrale/physiologie , Méthode en double aveugle , Électroconvulsivothérapie , Études de suivi , Humains , Inventaire de personnalité , Cortex préfrontal/physiopathologie , Résultat thérapeutique
10.
Opt Express ; 16(25): 20522-9, 2008 Dec 08.
Article de Anglais | MEDLINE | ID: mdl-19065191

RÉSUMÉ

We develop a novel method for structure determination of confined fluids using diffraction-grating-based x-ray interferometry.Within this approach, diffraction from a microfluidic array, which acts both as confinement and transmission diffraction grating, provides the reference wave, whereas the density modulations of the confined fluid, acting as a weak phase object, generate the object wave. The ensemble-averaged density profile of the fluid perpendicular to the confining channel is then unambiguously obtained from the interference between the reference and object waves by direct Fourier inversion.


Sujet(s)
Mélanges complexes/composition chimique , Conception assistée par ordinateur , Interférométrie/instrumentation , Microfluidique/instrumentation , Modèles théoriques , Réfractométrie/instrumentation , Diffraction des rayons X/instrumentation , Simulation numérique , Conception d'appareillage , Analyse de panne d'appareillage , Lumière , Diffusion de rayonnements
11.
Phys Rev Lett ; 101(13): 136103, 2008 Sep 26.
Article de Anglais | MEDLINE | ID: mdl-18851466

RÉSUMÉ

Using x-ray diffraction from microfluidic channel arrays, we have determined concentration profiles of charge-stabilized silica colloids (radius 60+/-2 nm) confined between two like-charged dielectric walls at a few hundred nanometer distance. In solutions of very low ionic strength, strongly repulsive Coulomb interactions drive the colloids toward the central region between the walls. The addition of a small quantity of salt ions (0.2 mM) causes a dense colloidal monolayer to be trapped near the walls.

12.
Encephale ; 33(4 Pt 1): 544-9, 2007 Sep.
Article de Français | MEDLINE | ID: mdl-18033141

RÉSUMÉ

BACKGROUND: Bipolar mood disorders, after starting at adulthood, may remain active throughout life, but bipolar disorders may only be revealed in later life. Indeed, Yet few data on bipolar disorders in the elderly have been reported in the litterature. The influence of normal aging on the outcome of the disease as well as the specific prognosis of bipolar disorders in the elderly has occasionally been studied. Eventually Finally, and contrasting with adults, few studies comparing the various subtypes of mood disorders were have been performed in the elderly. OBJECTIVES: We therefore developed a study in patients aged 65 or above, in order to evaluate the course (recurrences) of bipolar disorders, compared to recurring depressions and single depressions, and to determine the influence of recurrences on the outcome of bipolar disorders. METHOD: Patients aged over 65 years were inpatients admitted to the department of psychiatry in 2000 for one of the three previously mentioned diagnoses according to DSM IV. Retrospective data were collected from medical reports. Prospectively, data were collected from the general practitioner of each patient (relying on telephone calls), before statistical analysis was performed. RESULTS: Our study demonstrates a more severe outcome for bipolar disorders compared to recurring depressions and single depressions. Patients with bipolar disorders have a higher prevalence of psychiatric recurrences. Furthermore, the greater the number of previous relapses (or the longer the duration and intensity of the disease), the higher the risk of future new future recurrences both in bipolar disorders and recurring depressions. An age of onset of bipolar disorders before 60 years and more than 5 in-hospital admissions increase the risk of recurrences. CONCLUSION: We originally compare the outcome of bipolar disorders in the elderly, to recurring depressions and single depressions. We confirm the fatal outcome of recurrences in bipolar disorders in old age. Bipolar disorders in the elderly should be considered as a real public health care problem: strategies to minimize the number of episodes experienced by patients with bipolar illness must be pursued aggressively throughout life.


Sujet(s)
Trouble bipolaire/épidémiologie , Trouble bipolaire/psychologie , Trouble dépressif/épidémiologie , Trouble dépressif/psychologie , Sujet âgé , Sujet âgé de 80 ans ou plus , Études de cohortes , Diagnostic and stastistical manual of mental disorders (USA) , Femelle , Humains , Mâle , Adulte d'âge moyen , Récidive
13.
Ann Oncol ; 16(12): 1882-8, 2005 Dec.
Article de Anglais | MEDLINE | ID: mdl-16216833

RÉSUMÉ

BACKGROUND: Survival after diagnosis of cancer is a key criterion for cancer control. Major survival differences between time periods and countries have been reported by the EUROCARE studies. We investigated whether similar differences by period and region existed in Switzerland. METHODS: Survival of 11,376 cases of primary invasive female breast cancer diagnosed between 1988 and 1997 and registered in seven Swiss cancer registries covering a population of 3.5 million was analysed. RESULTS: Comparing the two periods 1988-1992 and 1993-1997, age-standardized 5 year relative survival improved globally from 77% to 81%. Furthermore, multivariate analysis adjusting for age, tumour size and nodal involvement identified regional survival differences. Survival was lowest in the rural parts of German-speaking eastern Switzerland and highest in urbanised regions of the Latin- and German-speaking northwestern parts of the country. CONCLUSIONS: This study confirms that survival differences are present even in a small and affluent, but culturally diverse, country like Switzerland, raising the issue of heterogeneity in access to care and quality of treatment.


Sujet(s)
Tumeurs du sein/diagnostic , Tumeurs du sein/mortalité , Adolescent , Adulte , Répartition par âge , Sujet âgé , Sujet âgé de 80 ans ou plus , Femelle , Humains , Adulte d'âge moyen , Enregistrements/statistiques et données numériques , Caractéristiques de l'habitat , Taux de survie , Suisse/épidémiologie
14.
Proc Natl Acad Sci U S A ; 101(47): 16472-7, 2004 Nov 23.
Article de Anglais | MEDLINE | ID: mdl-15546992

RÉSUMÉ

Classical cadherins are primary mediators of calcium-dependent cell interactions in multicellular organisms. Organized in five tandemly repeated E-cadherin (EC) modules, the extracellular segments of these membrane-spanning glycoproteins interact homophilically between opposing cells to create highly regulated patterns of attachment stabilized by cytoskeletal elements inside the cells. Despite many structural and functional studies, a significant controversy exists in regard to the organization of cadherin binding in adhesion sites. Supported by considerable evidence, perhaps the most widely held view is that opposing N-terminal EC1-EC2 (EC12) domains form a "zipper" of bonds. However, immobilized on two atomically smooth surfaces and pushed to adhesive contact, opposing cadherins become fully interdigitated and unbind through three discrete jumps comparable with domain dimensions when pulled apart. So the question remains as to whether mechanical adhesion strength emanates solely from interactions between the peripheral N-terminal domains or involves multiple overlapping domains. It is also unclear whether a primary adhesion complex is formed by a single opposing pair of cadherins or whether the complex involves a more complicated network of cis-bonded multimers. To address these questions, we used a special jump/ramp mode of force spectroscopy to test isolated pairwise interactions between recombinant fragments of ECs. Besides the formation of strong trans-bonded dimers, we find a remarkable hierarchy of rupture strengths for bonds between the full five-domain fragments that suggests multiple mechanical functions for cadherins, perhaps providing distinct properties needed for transient-specific recognition as well as stable tissue formation.


Sujet(s)
Cadhérines/composition chimique , Cadhérines/physiologie , Animaux , Séquence nucléotidique , Phénomènes biomécaniques , Cadhérines/génétique , ADN complémentaire/génétique , Techniques in vitro , Souris , Modèles chimiques , Fragments peptidiques/composition chimique , Fragments peptidiques/génétique , Structure tertiaire des protéines , Protéines recombinantes/composition chimique , Protéines recombinantes/génétique
15.
J Gen Virol ; 83(Pt 5): 1005-1012, 2002 May.
Article de Anglais | MEDLINE | ID: mdl-11961254

RÉSUMÉ

Human cytomegalovirus (HCMV) UL53 belongs to a family of conserved herpesvirus genes. In this work, the expression and localization of the UL53 gene product was analysed. Results obtained showed that pUL53 is a new structural protein. In infected human fibroblasts, pUL53 localizes in cytoplasmic perinuclear granular formations together with other structural viral proteins. In the nucleus, pUL53 forms patches at the nuclear periphery and co-localizes with lamin B at the internal nuclear membrane level. Immunoelectron microscopy studies have disclosed that nuclear pseudo-inclusions are labelled, whereas nucleocapsid formations within the intranuclear skein are negative. Furthermore, the mature virus particle maintains pUL53 at its tegumental level. These data suggest that pUL53 could be involved either in nucleocapsid maturation or in the egress of nucleocapsids from the nucleus to the cytoplasm through the nuclear membrane, a role compatible with the function hypothesized for UL31, its positional homologue in herpes simplex virus type 1.


Sujet(s)
Cytomegalovirus/composition chimique , Protéines virales structurales/analyse , Humains , Microscopie immunoélectronique , Protéines virales structurales/physiologie , Virion/composition chimique
16.
J Clin Invest ; 108(12): 1817-24, 2001 Dec.
Article de Anglais | MEDLINE | ID: mdl-11748265

RÉSUMÉ

In animal models of asthma, interleukin-13 (IL-13) induces goblet cell metaplasia, eosinophil infiltration of the bronchial mucosa, and bronchial hyperreactivity, but the basis of its effects on airway epithelia remain unknown. Lesions of the epithelial barrier, frequently observed in asthma and other chronic lung inflammatory diseases, are repaired through proliferation, migration, and differentiation of epithelial cells. An inflammatory process may then, therefore, influence epithelial regeneration. We have thus investigated the effect of IL-13 on mucociliary differentiation of human nasal epithelial cells in primary culture. We show that IL-13 alters ciliated cell differentiation and increases the proportion of secretory cells. IL-13 downregulates the actin-binding protein ezrin and other cytoskeletal components. IL-13 also impairs lateral cell contacts and interferes with the apical localization of ezrin seen in differentiated ciliated cells. In addition, an IL-4 antagonistic mutant protein (Y124D), which binds to the IL-4 receptor alpha subunit, a common chain of IL-4 and IL-13 receptors, inhibits IL-13's effects. IL-13 also decreases ciliary beat frequency in a time- and dose-dependent manner. These results suggest that, in human allergic asthmatic responses, IL-13 affects both ciliated and secretory cell differentiation, leading to airway damage and obstruction.


Sujet(s)
Asthme/étiologie , Bronches/effets des médicaments et des substances chimiques , Interleukine-13/pharmacologie , Bronches/cytologie , Différenciation cellulaire/effets des médicaments et des substances chimiques , Polarité de la cellule , Cellules cultivées , Cils vibratiles/effets des médicaments et des substances chimiques , Cils vibratiles/physiologie , Protéines du cytosquelette , Relation dose-effet des médicaments , Cellules épithéliales/effets des médicaments et des substances chimiques , Cellules épithéliales/physiologie , Humains , Interleukine-4/physiologie , Mucine-2 , Mucines/génétique , Muqueuse/cytologie , Muqueuse/effets des médicaments et des substances chimiques , Phosphoprotéines/analyse
17.
Blood ; 98(13): 3762-9, 2001 Dec 15.
Article de Anglais | MEDLINE | ID: mdl-11739184

RÉSUMÉ

Treatment of patients with adult T-cell leukemia-lymphoma (ATLL) using conventional chemotherapy has limited benefit because human T-cell leukemia virus type 1 (HTLV-1) cells are resistant to most apoptosis-inducing agents. The recent report that arsenic trioxide induces apoptosis in HTLV-1-transformed cells prompted investigation of the mechanism of action of this drug in HTLV-1 and HTLV-2 interleukin-2-independent T cells and in HTLV-1-immortalized cells or in ex vivo ATLL samples. Fluorescence-activated cell sorter analysis, fluorescence microscopy, and measures of mitochondrial membrane potential (Delta Psi m) demonstrated that arsenic trioxide alone was sufficient to induce programmed cell death in all HTLV-1 and -2 cells tested and in ATLL patient samples. I kappa B-alpha phosphorylation strongly decreased, and NF-kappa B translocation to the nucleus was abrogated. Expression of the antiapoptotic protein Bcl-X(L), whose promoter is NF-kappa B dependent, was down-regulated. The collapse of Delta Psi m and the release of cytochrome c to the cytosol resulted in the activation of caspase-3, as demonstrated by the cleavage of PARP. A specific caspase-3 inhibitor (Ac-DEVD-CHO) could reverse this phenotype. The antiapoptotic factor Bcl-2 was then cleaved, converting it to a Bax-like death effector. These results demonstrated that arsenic trioxide induces apoptosis in HTLV-1- and -2-infected cells through activation of the caspase pathway.


Sujet(s)
Apoptose/effets des médicaments et des substances chimiques , Composés de l'arsenic/pharmacologie , Caspases/métabolisme , Virus T-lymphotrope humain de type 1/physiologie , Virus T-lymphotrope humain de type 2/physiologie , Protéines I-kappa B , Leucémie-lymphome à cellules T de l'adulte/anatomopathologie , Oxydes/pharmacologie , Protéines proto-oncogènes c-bcl-2/métabolisme , Trioxyde d'arsenic , Caspase-3 , Lignée de cellules transformées , Noyau de la cellule/métabolisme , Cytochromes de type c/métabolisme , Protéines de liaison à l'ADN/métabolisme , Cytométrie en flux , Humains , Interféron alpha/pharmacologie , Leucémie-lymphome à cellules T de l'adulte/virologie , Potentiels de membrane , Microscopie de fluorescence , Mitochondries/ultrastructure , Inhibiteur alpha de NF-KappaB , Facteur de transcription NF-kappa B/métabolisme , Phosphorylation , Protéines proto-oncogènes/analyse , Protéines proto-oncogènes c-bcl-2/analyse , Protéine p53 suppresseur de tumeur/analyse , Protéine Bax , Protéine bcl-X
18.
Microbes Infect ; 3(12): 1005-13, 2001 Oct.
Article de Anglais | MEDLINE | ID: mdl-11580987

RÉSUMÉ

Human cytomegalovirus (CMV) infection of bone marrow transplant recipients can cause pancytopenia, as well as life-threatening interstitial pneumonia. CMV replicates actively in bone marrow stromal cells, whereas it remains latent in hematopoietic progenitors. Our aim was to study the influence of CMV infection on adherence of CD34(+) cells to the myofibroblastic component of human bone marrow and examine transmission of virus from myofibroblasts to CD34(+) cells. We show that smooth actin, but not fibronectin, organization is markedly modified by CMV infection of bone marrow stromal myofibroblasts. Nonetheless, CMV infection led to increased adherence of the CD34(+) progenitor cell line, KG1a, relative to adherence to uninfected myofibroblasts from the same donors. Adherence of CD34(+) cells to infected bone marrow myofibroblasts resulted in transfer of virions and viral proteins through close cell-to-cell contacts. This phenomenon may play a role in the pathophysiology of CMV bone marrow infection and in eventual virus dissemination.


Sujet(s)
Cellules de la moelle osseuse/virologie , Cytomegalovirus/pathogénicité , Cellules souches hématopoïétiques/physiologie , Actines/analyse , Antigènes CD34/analyse , Adhérence cellulaire , Lignée cellulaire , Fibronectines/analyse , Cellules souches hématopoïétiques/virologie , Humains , Phosphoprotéines/métabolisme , Cellules stromales/virologie , Protéines de la matrice virale/métabolisme , Réplication virale
19.
Hum Mutat ; 18(5): 388-96, 2001 Nov.
Article de Anglais | MEDLINE | ID: mdl-11668632

RÉSUMÉ

Desmin-related myopathy is a familial or sporadic disease characterized by skeletal muscle weakness and cardiomyopathy as well as the presence of intracytoplasmic aggregates of desmin-reactive material in the muscle cells. Previously, two kinds of deletions and eight missense mutations have been identified in the desmin gene and proven to be responsible for the disorder. The present study was conducted to determine structural and functional defects in a pathogenic desmin variant that caused a disabling disorder in an isolated case presenting with distal and proximal limb muscle weakness and cardiomyopathy. We identified a novel heterozygous Q389P desmin mutation located at the C-terminal part of the rod domain as the causative mutation in this case. Transfection of desmin cDNA containing the patient's mutation into C2.7, MCF7, and SW13 cells demonstrated that the Q389P mutant is incapable of constructing a functional intermediate filament network and has a dominant negative effect on filament formation. We conclude that Q389P mutation is the molecular event leading to the development of desmin-related myopathy.


Sujet(s)
Desmine/génétique , Desmine/métabolisme , Variation génétique/génétique , Mutation faux-sens/génétique , Myopathies congénitales structurales/génétique , Myopathies congénitales structurales/physiopathologie , Adulte , Motifs d'acides aminés , Séquence d'acides aminés , Animaux , Séquence nucléotidique , Cardiomyopathies/complications , Cardiomyopathies/génétique , Cardiomyopathies/physiopathologie , Lignée cellulaire , Cristallines/génétique , Analyse de mutations d'ADN , Desmine/composition chimique , Gènes dominants/génétique , Humains , Filaments intermédiaires/métabolisme , Filaments intermédiaires/anatomopathologie , Mâle , Souris , Adulte d'âge moyen , Données de séquences moléculaires , Faiblesse musculaire/complications , Faiblesse musculaire/génétique , Faiblesse musculaire/physiopathologie , Myopathies congénitales structurales/complications , Structure tertiaire des protéines , Alignement de séquences , Relation structure-activité , Cellules cancéreuses en culture
20.
J Virol ; 75(22): 11166-77, 2001 Nov.
Article de Anglais | MEDLINE | ID: mdl-11602756

RÉSUMÉ

Whereas human immunodeficiency virus (HIV) infects various cell types by fusion at the plasma membrane, we observed a different entry route in human primary macrophages, in which macropinocytosis is active. Shortly after exposure of macrophages to HIV-1 and irrespective of viral envelope-receptor interactions, particles were visible in intracellular vesicles, which were identified as macropinosomes. Most virions appeared subsequently degraded. However, fusion leading to capsid release in the cytosol and productive infection could take place inside vesicles when particles were properly enveloped. These observations provide new insights into HIV-1 interactions with a cell target relevant to pathogenesis. They may have implications for the design of soluble inhibitors aimed at interfering with the fusion or entry processes.


Sujet(s)
VIH-1 (Virus de l'Immunodéficience Humaine de type 1)/physiologie , Macrophages/virologie , Pinocytose , Cytosol/composition chimique , Protéine de capside p24 du VIH/analyse , Cellules HeLa , Humains , Concentration en ions d'hydrogène , Macrophages/ultrastructure , Microscopie électronique
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