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1.
Acta Paediatr ; 103(9): 977-83, 2014 Sep.
Article de Anglais | MEDLINE | ID: mdl-24837972

RÉSUMÉ

AIM: A small percentage of complicated infantile haemangiomas need early, safe and effective treatment, and the option of off-label systemic propranolol treatment has been in existence since 2008. The aim of this study was to provide greater insight into the drug's efficacy and side effects. METHODS: We report our retrospective experiences of 207 paediatric patients treated with systemic propranolol for complicated infantile haemangiomas, which were photographed and analysed with a specific haemangioma score. RESULTS: Systemic treatment was successful in 99.5% of the patients. The haemangioma score before treatment was 8.3 ± 3.3 and the score at the end of the treatment was 1.5 ± 1.4. The reduction in the haemangiomas was significant and did not show any differences when distributed according to different localisations or to the patients' ages. Relevant side effects that may have made it necessary to discontinue the treatment were not observed. However, there was a statistically significant reduction in heart rate during the first six in-hospital drug applications. CONCLUSION: Our study demonstrates that systemic propranolol treatment is a highly effective treatment that is nearly always safe. These findings are a milestone for particularly complicated haemangiomas and provide highly valuable information on this drug treatment.


Sujet(s)
Hémangiome/traitement médicamenteux , Propranolol/usage thérapeutique , Tumeurs cutanées/traitement médicamenteux , Femelle , Hémangiome/complications , Humains , Nourrisson , Mâle , Études rétrospectives , Tumeurs cutanées/complications , Résultat thérapeutique
2.
Int J Pediatr Otorhinolaryngol ; 75(3): 368-75, 2011 Mar.
Article de Anglais | MEDLINE | ID: mdl-21208666

RÉSUMÉ

OBJECTIVE: Hemangiomas of the nasal tip (HNT) are commonly described as "Cyrano" or "Pinocchio nose". They may cause significant aesthetic and functional impairment. It is still controversial how and when HNT should be treated. The risk of severe complications like irreversible contour deformities, growth disturbance, ulcerations, and nasal obstruction may obligate a therapeutic intervention. The aim of this study is to overview and to analyze different therapeutic approaches which were practiced over the last decade in two specialized centers. METHODS: This is a retrospective study which includes the analysis of demographic parameters, extent of the lesion, therapeutic interventions, outcome, and follow-up interventions. The analysis includes a blinded evaluation of photographic series for evaluation of the extension at the time of presentation and of the final outcome. RESULTS: Twenty-three children with HNT were analyzed who presented from 04/01/1998 to 03/31/2009. The age at presentation ranged from 1 to 63 months. On 6 patients (26%) conventional surgery was performed, 6 (26%) were treated with Nd:YAG laser, 6 (26%) were only observed, in 3 cases (13%) cryotherapy and in 2 patients (9%) treatment with Propranolol was performed. The results were evaluated between 9 months and 10.5 years after treatment (mean: 35.5 months). Limited lesions which were only observed showed a good tendency of regression. Significant wound healing disturbance and scar formation was observed after Nd:YAG laser therapy. Secondary rhinoplasty in adulthood was recommended to two patients. CONCLUSION: Limited lesions do not require therapy. The results with Propranolol are encouraging. Laser- and cryo-therapy have to be critically reevaluated. Treatment of choice for lesions that are not suitable for beta blockers and residual disease is conventional surgery.


Sujet(s)
Hémangiome/thérapie , Tumeurs du nez/thérapie , Nez/chirurgie , Antagonistes bêta-adrénergiques/usage thérapeutique , Enfant d'âge préscolaire , Cicatrice/étiologie , Cryothérapie , Esthétique , Femelle , Études de suivi , Humains , Nourrisson , Nouveau-né , Thérapie laser , Lasers à solide , Mâle , Propranolol/usage thérapeutique , Études rétrospectives , Cicatrisation de plaie
4.
Hautarzt ; 60(12): 1013-6, 2009 Dec.
Article de Allemand | MEDLINE | ID: mdl-19859669

RÉSUMÉ

Small hemangiomas sometimes produce large findings. Depending on localization, local therapy is not always possible. According to a case described in the literature, a hemangioma in an infant regressed following cardiologically indicated Propranolol. This experience has been used in numerous other cases since then and Propranolol has been administered for the indication of a hemangioma. Even in cases of very large hemangiomas rapid improvement has been observed; successful results persisted even after discontinuation. Particularly in cases of problematic localisation, such as in the eye area, prompt therapeutic success is important in order to prevent blindness. Relevant studies are in the preparatory phase.


Sujet(s)
Antagonistes bêta-adrénergiques/usage thérapeutique , Tumeurs de la face/traitement médicamenteux , Hémangiome/traitement médicamenteux , Propranolol/usage thérapeutique , Tumeurs cutanées/traitement médicamenteux , Administration par voie orale , Antagonistes bêta-adrénergiques/administration et posologie , Pression sanguine/effets des médicaments et des substances chimiques , Tumeurs de la face/congénital , Femelle , Études de suivi , Hémangiome/congénital , Humains , Nourrisson , Nouveau-né , Mâle , Utilisation hors indication , Propranolol/administration et posologie , Propranolol/effets indésirables , Tumeurs cutanées/congénital
5.
Hautarzt ; 53(1): 34-6, 2002 Jan.
Article de Allemand | MEDLINE | ID: mdl-11963220

RÉSUMÉ

We describe five cases of recurrent palmoplantar hidradenitis in children. The pathogenesis of this highly characteristic disease presenting with painful erythematous papules and nodules involving palms of the hands, soles of the feet, or both is not clear at the moment. One possible mechanism is a temporal relationship between exposure to dampness and cold, which also applied in four of these children. The self-limited disease tends to reappear. After thoroughly informing the children and their parents on avoiding provoking factors, all children experienced freedom from the disease during a 12-month follow-up.


Sujet(s)
Dermatoses du pied/diagnostic , Dermatoses de la main/diagnostic , Hidrosadénite/diagnostic , Enfant , Enfant d'âge préscolaire , Érythème/diagnostic , Érythème/étiologie , Femelle , Dermatoses du pied/étiologie , Dermatoses de la main/étiologie , Hidrosadénite/étiologie , Humains , Nourrisson , Mâle , Facteurs de risque
6.
Neuroendocrinology ; 74(5): 335-46, 2001 Nov.
Article de Anglais | MEDLINE | ID: mdl-11694765

RÉSUMÉ

The neural cell adhesion molecule (NCAM) and its polysialylated isoform (PSA-NCAM) have been shown to influence the proliferation, differentiation and survival of different cell types. Here, we report the pattern of expression of NCAM and PSA-NCAM in the anterior lobe (AL) of the pituitary gland of the adult mouse. We demonstrate that the majority of cells express NCAM, while PSA-NCAM is retained mostly on corticotropes. Analysis of bromodeoxyuridine (BrdU) incorporation shows that the presence of PSA-NCAM on corticotropes is not related to proliferation but most likely to their functional properties. We subsequently analyzed defects induced by NCAM deficiency in adult NCAM knockout mice. In these mice, all secretory cell types in the AL are present and their distribution within the gland is similar to that in wild-type mice. However, proliferation of AL cells is significantly increased. In particular, more BrdU-positive cells are detected among somatotropes and mammotropes in NCAM-deficient mice. In addition, the percentages of secretory cells are changed: somatotropes are more numerous while the number of corticotropes is reduced. These data demonstrate the involvement of NCAM in the proper generation and/or maintenance of the different cell populations in the AL and suggest the importance of PSA in corticotrope functioning.


Sujet(s)
Mutation/physiologie , Molécule d'adhérence cellulaire neurale L-1 , Molécules d'adhérence cellulaire neurales/génétique , Adénohypophyse/cytologie , Adénohypophyse/métabolisme , Animaux , Numération cellulaire , Différenciation cellulaire/physiologie , Hormone de croissance/métabolisme , Mâle , Souris , Souris de lignée C57BL , Molécules d'adhérence cellulaire neurales/déficit , Molécules d'adhérence cellulaire neurales/métabolisme , Prolactine/métabolisme , Valeurs de référence , Acides sialiques/métabolisme
7.
Neuroscience ; 105(4): 1019-30, 2001.
Article de Anglais | MEDLINE | ID: mdl-11530239

RÉSUMÉ

The germinative ventricular zone of embryonic brain contains neural lineage progenitor cells that give rise to neurons, astrocytes and oligodendrocytes. The ability to generate neurons persists at adulthood in restricted brain areas. During development, many growth factors exert their effects by interacting with tyrosine kinase receptors and activate the phosphatidylinositol 3-kinase and the Ras/MAP kinase pathways. By its ability to modulate these pathways, the recently identified Src homology 2 domain-containing inositol polyphosphate 5-phosphatase 2, SHIP2, has the potential to regulate neuronal development. Using in situ hybridization technique with multiple synthetic oligonucleotides, we demonstrated that SHIP2 mRNA was highly expressed in the ventricular zone at early embryonic stages and subventricular zones at latter stages of brain and spinal cord and in the sympathetic chain. No significant expression was seen in differentiated fields. This restricted expression was maintained from embryonic day 11.5 to birth. In the periphery, large expression was detected in muscle and kidney and moderate expression in thyroid, pituitary gland, digestive system and bone. In the adult brain, SHIP2 was mainly restricted in structures containing neural stem cells such as the anterior subventricular zone, the rostral migratory stream and the olfactory tubercle. SHIP2 was also detected in the choroid plexuses and the granular layer of the cerebellum. The specificity of SHIP2 expression in neural stem cells was further demonstrated by (i) the dramatic increase in SHIP2 mRNA signal in neural cell adhesion molecule (N-CAM)-deficient mice, which present an accumulation of progenitor cells in the anterior subventricular zone and the rostral migratory stream, (ii) the abundant expression of 160-kDa SHIP2 by western blotting in proliferating neurospheres in culture and its downregulation in non-proliferating differentiated neurospheres. In conclusion, the close correlation between the pattern of SHIP2 expression in the brain and the proliferative and early differentiative events suggests that the phosphatase SHIP2 may have important roles in neural development.


Sujet(s)
Vieillissement/métabolisme , Encéphale/embryologie , Encéphale/métabolisme , Phosphoric monoester hydrolases/métabolisme , Animaux , Cellules cultivées , Techniques cytologiques , Femelle , Foetus/métabolisme , Souris , Souris de lignée BALB C , Souris de lignée C57BL , Sondes moléculaires , Molécules d'adhérence cellulaire neurales/déficit , Neurones/métabolisme , Phosphatidylinositol-3,4,5-trisphosphate 5-phosphatases , Phosphoric monoester hydrolases/génétique , ARN messager/métabolisme , Distribution tissulaire
8.
Mol Neurobiol ; 24(1-3): 53-64, 2001.
Article de Anglais | MEDLINE | ID: mdl-11831554

RÉSUMÉ

Since its first description the polysialylated form of NCAM (PSA-NCAM) is thought to be a major regulator of cell-cell interactions in the nervous system. Over the past few years many crucial questions have been answered concerning PSA biosynthesis and function. Among these are the identification and cloning of the key enzymes that are responsible for its synthesis and the fact that expression of PSA is not restricted to developmental stages but maintained in the adult nervous system. In the adult, PSA has been shown to be not only a marker of structural plasticity but seems to be a major player in these processes. Originally suggested to be a purely anti-adhesive factor, modulating cell-cell interactions in general and by this allowing plasticity, there is now increasing evidence that this might not be the whole story. Instead, it appears possible that PSA-NCAM interacts with secreted signaling molecules and by this fulfills a more instructive function in brain plasticity.


Sujet(s)
Phénomènes physiologiques du système nerveux , Molécule d'adhérence cellulaire neurale L-1 , Molécules d'adhérence cellulaire neurales/physiologie , Acides sialiques/physiologie , Animaux , Axones/physiologie , Communication cellulaire , Mouvement cellulaire/physiologie , Humains , Plasticité neuronale/physiologie
9.
Hum Mol Genet ; 9(20): 3101-10, 2000 Dec 12.
Article de Anglais | MEDLINE | ID: mdl-11115855

RÉSUMÉ

Prader-Willi syndrome (PWS) is a complex neurogenetic disorder with considerable clinical variability that is thought in large part to be the result of a hypothalamic defect. PWS results from the absence of paternal expression of imprinted genes localized in the 15q11-q13 region; however, none of the characterized genes has so far been shown to be involved in the etiology of PWS. Here, we provide a detailed investigation of a mouse model deficient for NECDIN: Linked to the mutation, a neonatal lethality of variable penetrance is observed. Viable NECDIN: mutants show a reduction in both oxytocin-producing and luteinizing hormone-releasing hormone (LHRH)-producing neurons in hypothalamus. This represents the first evidence of a hypothalamic deficiency in a mouse model of PWS. NECDIN:-deficient mice also display increased skin scraping activity in the open field test and improved spatial learning and memory in the Morris water maze. The latter features are reminiscent of the skin picking and improved spatial memory that are characteristics of the PWS phenotype. These striking parallels in hypothalamic structure, emotional and cognitive-related behaviors strongly suggest that NECDIN is responsible for at least a subset of the multiple clinical manifestations of PWS.


Sujet(s)
Protéines de tissu nerveux/génétique , Neurones/physiologie , Protéines nucléaires/génétique , Syndrome de Prader-Willi/génétique , Animaux , Cognition/physiologie , Troubles de la cognition/génétique , Modèles animaux de maladie humaine , Hormone de libération des gonadotrophines/métabolisme , Hypothalamus/métabolisme , Hypothalamus/physiologie , Souris , Souris knockout , Protéines de tissu nerveux/déficit , Protéines de tissu nerveux/physiologie , Protéines nucléaires/déficit , Protéines nucléaires/physiologie , Ocytocine/métabolisme , Syndrome de Prader-Willi/psychologie , Performance psychomotrice/physiologie
10.
Immunity ; 13(3): 355-64, 2000 Sep.
Article de Anglais | MEDLINE | ID: mdl-11021533

RÉSUMÉ

KARAP/DAP12 is a transmembrane polypeptide with an intracytoplasmic immunoreceptor tyrosine-based activation motif (ITAM). KARAP/DAP12 is associated with several activating cell surface receptors in hematopoietic cells. Here, we report that knockin mice bearing a nonfunctional KARAP/DAP12 ITAM present altered innate immune responses. Although in these mice NK cells are present and their repertoire of inhibitory MHC class I receptors is intact, the NK cell spectrum of natural cytotoxicity toward tumor cell targets is restricted. KARAP/DAP12 loss-of-function mutant mice also exhibit a dramatic accumulation of dendritic cells in muco-cutaneous epithelia, associated with an impaired hapten-specific contact sensitivity. Thus, despite its homology with CD3zeta and FcRgamma, KARAP/DAP12 plays a specific role in innate immunity, emphasizing the nonredundancy of these ITAM-bearing polypeptides in hematopoietic cells.


Sujet(s)
Antigènes Ly , Cytotoxicité immunologique/génétique , Cellules dendritiques/immunologie , Cellules tueuses naturelles/immunologie , Souris knockout/immunologie , Récepteurs immunologiques/déficit , Récepteurs immunologiques/génétique , Protéines adaptatrices de la transduction du signal , Séquence d'acides aminés , Animaux , Cellules de la moelle osseuse/immunologie , Cellules de la moelle osseuse/métabolisme , Lignée cellulaire , Mouvement cellulaire/génétique , Mouvement cellulaire/immunologie , Croisements génétiques , Cellules dendritiques/métabolisme , Cellules épithéliales/immunologie , Ciblage de gène , Immunophénotypage , Cellules tueuses naturelles/métabolisme , Lectines de type C , Glycoprotéines membranaires/biosynthèse , Protéines membranaires , Souris , Souris de lignée BALB C , Souris de lignée C57BL , Souris de lignée CBA , Souris transgéniques , Données de séquences moléculaires , Muqueuse/cytologie , Muqueuse/immunologie , Récepteurs immunologiques/physiologie , Récepteurs de cellules NK de type lectine , Délétion de séquence , Transduction du signal/génétique , Transduction du signal/immunologie , Peau/cytologie , Peau/immunologie
11.
J Neurosci ; 20(14): 5234-44, 2000 Jul 15.
Article de Anglais | MEDLINE | ID: mdl-10884307

RÉSUMÉ

Functional properties of the neural cell adhesion molecule (NCAM) are strongly influenced by polysialylation. We used gene-targeting to generate mice lacking ST8SiaIV/PST-1, one of the polysialyltransferases responsible for addition of polysialic acid (PSA) to NCAM. Mice homozygous for the null mutation reveal normal development of gross anatomical features. In contrast to NCAM-deficient mice, olfactory precursor cells in the rostral migratory stream express PSA and follow their normal pathway. Furthermore, delamination of mossy fibers in the hippocampal CA3 region, as found in NCAM-deficient mice, does not occur in ST8SiaIV mutants. However, during postnatal development these animals show a decrease of PSA in most brain regions compared to wild-type animals. Loss of PSA in the presence of NCAM protein but in the absence of obvious histological changes allowed us to directly address the role of PSA in synaptic plasticity. Schaffer collateral-CA1 synapses, which express PSA in wild types, showed impaired long-term potentiation (LTP) and long-term depression (LTD) in adult mutants. This impairment was age-dependent, following the time course of developmental disappearance of PSA. Contrary to NCAM mutant mice, LTP in ST8SiaIV mutants was undisturbed at mossy fiber-CA3 synapses, which do not express PSA in wild-type mice. The results demonstrate an essential role for ST8SiaIV in synaptic plasticity in hippocampal CA1 synapses, whereas PSA produced by different polysialyltransferase or polysialyltransferases at early stages of differentiation regulates migration of neural precursor cells and correct lamination of mossy fibers. We suggest that NCAM but not PSA is likely to be important for LTP in the hippocampal CA3 region.


Sujet(s)
Molécules d'adhérence cellulaire neurales/métabolisme , Plasticité neuronale/physiologie , Neurones/métabolisme , Acides sialiques/métabolisme , Sialyltransferases/déficit , Vieillissement , Animaux , Encéphale/métabolisme , Potentiels post-synaptiques excitateurs , Hippocampe/métabolisme , Techniques in vitro , Potentialisation à long terme/génétique , Souris , Souris de lignée C57BL , Mutants neurologiques de souris , Inhibition nerveuse/génétique , Neurones/cytologie , Sialyltransferases/génétique , Synapses/métabolisme
12.
Hautarzt ; 51(2): 86-9, 2000 Feb.
Article de Allemand | MEDLINE | ID: mdl-10743579

RÉSUMÉ

Two boys aged 6 and 9 years presented with persistent sharply circumscribed perianal erythema. One boy had no other skin findings; the other had additional lesions on the genitalia and extremities. The diagnosis of perianal streptococcal dermatitis was made after streptococci were cultured from skin swabs. This primarily childhood disease should be distinguished from candidiasis and perianal atopic dermatitis. As in our cases, topical therapy is usually ineffective and oral penicillin remains the treatment of choice.


Sujet(s)
Impétigo/diagnostic , Rectite/diagnostic , Infections à streptocoques/diagnostic , Streptococcus pyogenes , Administration par voie orale , Administration par voie topique , Enfant , Clioquinol/administration et posologie , Diagnostic différentiel , Humains , Impétigo/traitement médicamenteux , Mâle , Phénoxyméthylpénicilline/administration et posologie , Rectite/traitement médicamenteux , Infections à streptocoques/traitement médicamenteux , Streptococcus pyogenes/effets des médicaments et des substances chimiques
13.
Proc Natl Acad Sci U S A ; 97(4): 1823-8, 2000 Feb 15.
Article de Anglais | MEDLINE | ID: mdl-10677540

RÉSUMÉ

In adult rodents, neurons are continually generated in the subventricular zone of the forebrain, from where they migrate tangentially toward the olfactory bulb, the only known target for these neuronal precursors. Within the main olfactory bulb, they ascend radially into the granule and periglomerular cell layers, where they differentiate mainly into local interneurons. The functional consequences of this permanent generation and integration of new neurons into existing circuits are unknown. To address this question, we used neural cell adhesion molecule-deficient mice that have documented deficits in the migration of olfactory-bulb neuron precursors, leading to about 40% size reduction of this structure. Our anatomical study reveals that this reduction is restricted to the granule cell layer, a structure that contains exclusively gamma-aminobutyric acid (GABA)ergic interneurons. Furthermore, mutant mice were subjected to experiments designed to examine the behavioral consequences of such anatomical alteration. We found that the specific reduction in the newly generated interneuron population resulted in an impairment of discrimination between odors. In contrast, both the detection thresholds for odors and short-term olfactory memory were unaltered, demonstrating that a critical number of bulbar granule cells is crucial only for odor discrimination but not for general olfactory functions.


Sujet(s)
Molécules d'adhérence cellulaire neurales/génétique , Neurones afférents/métabolisme , Bulbe olfactif/cytologie , Odorat/génétique , Animaux , Broxuridine , Division cellulaire/génétique , Immunohistochimie , Mâle , Mémoire à court terme , Souris , Souris transgéniques , Mutation , Prosencéphale/métabolisme , Performance psychomotrice
14.
Int J Dev Neurosci ; 18(2-3): 213-20, 2000.
Article de Anglais | MEDLINE | ID: mdl-10715576

RÉSUMÉ

The Neural Cell Adhesion Molecule (NCAM) serves as a temporally and spatially regulated modulator of a variety of cell-cell interactions. This review summarizes recent results of studies aimed at understanding its regulation of expression and biological function, thereby focussing on its polysialylated isoforms (PSA-NCAM). The detailed analysis of the expression of PSA and NCAM in the hippocampal mossy fiber system and the morphological consequences of PSA-NCAM deficiency in mice support the notion that the levels of expression of NCAM are important not only for the regulation and maintenance of structural changes, such as migration, axonal growth and fasciculation, but also for activity-induced plasticity. There is evidence that PSA-NCAM can specifically contribute to a presynaptic form of plasticity, namely long-term potentiation at hippocampal mossy fiber synapses. This is consistent with previous observations that NCAM-deficient mice show deficits in spatial learning and exploratory behavior. Furthermore, our data points to an important role of the hypothalamic-pituitary-adrenal axis, which is the principle adaptive response of the organism to environmental challenges, in the control of PSA-NCAM expression in the hippocampal formation. In particular, we evidence an inhibitory influence of corticosterone on PSA-NCAM expression.


Sujet(s)
Hippocampe/physiologie , Molécule d'adhérence cellulaire neurale L-1 , Molécules d'adhérence cellulaire neurales/physiologie , Plasticité neuronale/physiologie , Acides sialiques/physiologie , Animaux , Hippocampe/composition chimique
15.
J Neurosci ; 20(4): 1446-57, 2000 Feb 15.
Article de Anglais | MEDLINE | ID: mdl-10662835

RÉSUMÉ

In vertebrates, interneurons of the olfactory bulb (OB) are generated postnatally and throughout life at the subventricular zone of the forebrain. The neuronal precursors migrate tangentially through the forebrain using a well defined pathway, the rostral migratory stream (RMS), and a particular mode of migration in a chain-like organization. A severe size reduction of the OB represents the most striking morphological phenotype in neural cell adhesion molecule (NCAM)-deficient mice. This defect has been traced back to a migration deficit of the precursors in the RMS and linked to the lack of the polysialylated form of NCAM. In this study we investigate the morphological alterations and functional properties of the RMS in mice totally devoid of all isoforms of NCAM and polysialic acid (PSA). We show that a morphologically altered, but defined and continuous pathway exists in mutants, and we present in vivo and in vitro evidence that PSA-NCAM in the RMS is not essential for the formation and migration of chains. Instead, we find a massive gliosis associated with the formation of membrane specializations in a heterotypic manner, linking precursors to astrocytes. This finding and the over-representation and defasciculation of axons in the pathway suggest that important interactions between migrating cells and their stationary environment are perturbed in the mutants. Finally, we used transplantation experiments to demonstrate that lack of PSA-NCAM leads to a decrease but not a total blockade of migration and demonstrate that the mutant RMS is functional in transporting normal neuronal precursors to the OB.


Sujet(s)
Mouvement cellulaire/physiologie , Molécules d'adhérence cellulaire neurales/physiologie , Neurones/physiologie , Bulbe olfactif/physiologie , Prosencéphale/physiologie , Animaux , Axones/physiologie , Axones/ultrastructure , Ventricules cérébraux/cytologie , Ventricules cérébraux/physiologie , Croisements génétiques , Souris , Souris de lignée C57BL , Souris knockout , Molécules d'adhérence cellulaire neurales/composition chimique , Molécules d'adhérence cellulaire neurales/génétique , Névroglie/cytologie , Névroglie/physiologie , Névroglie/ultrastructure , Neurones/cytologie , Neurones/ultrastructure , Bulbe olfactif/malformations , Bulbe olfactif/ultrastructure , Voies olfactives/cytologie , Voies olfactives/physiologie , Techniques de culture d'organes , Prosencéphale/cytologie , Prosencéphale/ultrastructure , Isoformes de protéines/déficit , Isoformes de protéines/génétique , Isoformes de protéines/physiologie , Acides sialiques/génétique , Cellules souches/physiologie
16.
J Neurobiol ; 40(3): 343-55, 1999 Sep 05.
Article de Anglais | MEDLINE | ID: mdl-10440734

RÉSUMÉ

Mice deficient in the neural cell adhesion molecule (NCAM) show behavioral abnormalities as adults, including altered exploratory behavior, deficits in spatial learning, and increased intermale aggression. Here, we report increased anxiety-like behavior of homozygous (NCAM-/-) and heterozygous (NCAM/-) mutant mice in a light/dark avoidance test, independent of genetic background and gender. Anxiety-like behavior was reduced in both NCAM+/+ and NCAM-/- mice by systemic administration of the benzodiazepine agonist diazepam and the 5-HT1A receptor agonists buspirone and 8-OH-DPAT. However, NCAM-/- mice showed anxiolytic-like effects at lower doses of buspirone and 8-OH-DPAT than NCAM+/+ mice. Such increased response to 5-HT1A receptor stimulation suggests a functional change in the serotonergic system of NCAM-/- mice, likely involved in the control of anxiety and aggression. However, 5-HT1A receptor binding and tissue content of serotonin and its metabolite 5-hydroxyindolacetic acid were found unaltered in every brain area of NCAM-/- mice investigated, indicating that expression of 5-HT1A receptors as well as synthesis and release of serotonin are largely unchanged in NCAM-/- mice. We hypothesize a critical involvement of endogenous NCAM in serotonergic transmission via 5-HT1A receptors and inwardly rectifying K+ channels as the respective effector systems.


Sujet(s)
Anxiété/traitement médicamenteux , Anxiété/psychologie , Molécules d'adhérence cellulaire neurales/effets des médicaments et des substances chimiques , Récepteurs sérotoninergiques/effets des médicaments et des substances chimiques , 7-Dipropylamino-5,6,7,8-tétrahydro-1-naphtol/pharmacologie , 7-Dipropylamino-5,6,7,8-tétrahydro-1-naphtol/usage thérapeutique , Animaux , Anxiolytiques/pharmacologie , Anxiolytiques/usage thérapeutique , Autoradiographie , Fixation compétitive , Chimie du cerveau/physiologie , Buspirone , Diazépam/pharmacologie , Diazépam/usage thérapeutique , Comportement d'exploration/effets des médicaments et des substances chimiques , Génotype , Acide 5-hydroxy-indole-3-acétique/analyse , Mâle , Apprentissage du labyrinthe/effets des médicaments et des substances chimiques , Souris , Souris knockout , Souches mutantes de souris , Souris transgéniques , Canaux potassiques/effets des médicaments et des substances chimiques , Sérotonine/analyse , Agonistes des récepteurs de la sérotonine/pharmacologie , Agonistes des récepteurs de la sérotonine/usage thérapeutique , Comportement spatial/effets des médicaments et des substances chimiques
17.
Nature ; 399(6734): 366-70, 1999 May 27.
Article de Anglais | MEDLINE | ID: mdl-10360575

RÉSUMÉ

The sympathetic, parasympathetic and enteric ganglia are the main components of the peripheral autonomic nervous system, and are all derived from the neural crest. The factors needed for these structures to develop include the transcription factor Mash1, the glial-derived neurotrophic factor GNDF and its receptor subunits, and the neuregulin signalling system, each of which is essential for the differentiation and survival of subsets of autonomic neurons. Here we show that all autonomic ganglia fail to form properly and degenerate in mice lacking the homeodomain transcription factor Phox2b, as do the three cranial sensory ganglia that are part of the autonomic reflex circuits. In the anlagen of the enteric nervous system and the sympathetic ganglia, Phox2b is needed for the expression of the GDNF-receptor subunit Ret and for maintaining Mash1 expression. Mutant ganglionic anlagen also fail to switch on the genes that encode two enzymes needed for the biosynthesis of the neurotransmitter noradrenaline, dopamine-beta-hydroxylase and tyrosine hydroxylase, demonstrating that Phox2b regulates the noradrenergic phenotype in vertebrates.


Sujet(s)
Système nerveux autonome/embryologie , Gènes homéotiques , Protéines à homéodomaine/génétique , Protéines à homéodomaine/physiologie , Facteurs de croissance nerveuse , Crête neurale/embryologie , Facteurs de transcription/génétique , Facteurs de transcription/physiologie , Animaux , Facteurs de transcription à motif basique hélice-boucle-hélice , Protéines de liaison à l'ADN/métabolisme , Dopamine beta-monooxygenase/génétique , Système nerveux entérique/embryologie , Système nerveux entérique/physiologie , Récepteurs ErbB/génétique , Ganglions du système nerveux autonome/embryologie , Ganglions du système nerveux autonome/physiologie , Ganglions sensitifs/embryologie , Ganglions sensitifs/physiologie , Expression des gènes , Ciblage de gène , Facteur neurotrophique dérivé des cellules gliales , Souris , Mutagenèse par insertion , Protéines de tissu nerveux/génétique , Crête neurale/cytologie , Crête neurale/physiologie , Protéines proto-oncogènes/génétique , Récepteur ErbB-3 , Facteurs de transcription/métabolisme , Tyrosine 3-monooxygenase/génétique
18.
Nat Med ; 5(3): 286-91, 1999 Mar.
Article de Anglais | MEDLINE | ID: mdl-10086383

RÉSUMÉ

As in the development of many human cancers, in a transgenic mouse model of beta-cell carcinogenesis (Rip1Tag2), expression of neural cell adhesion molecule (NCAM) changes from the 120-kDa isoform in normal tissue to the 140/180-kDa isoforms in tumors. NCAM-deficient RiplTag2 mice, generated by crossing Rip1Tag2 mice with NCAM knockout mice, develop metastases, a tumor stage that is not seen in normal Rip1Tag2 mice. In contrast, overexpression of NCAM 120 in NCAM-deficient Rip1Tag2 mice prevents tumor metastasis. The results indicate that the loss of NCAM-mediated cell adhesion is one rate-limiting step in the actual metastatic dissemination of beta tumor cells.


Sujet(s)
Régulation de l'expression des gènes tumoraux , Insulinome/physiopathologie , Molécules d'adhérence cellulaire neurales/génétique , Tumeurs du pancréas/physiopathologie , Animaux , Évolution de la maladie , Dosage génique , Humains , Insulinome/génétique , Insulinome/métabolisme , Ilots pancréatiques/cytologie , Ilots pancréatiques/métabolisme , Mésoderme , Souris , Souris de lignée C57BL , Souris knockout , Souris transgéniques , Métastase tumorale , Molécules d'adhérence cellulaire neurales/physiologie , Tumeurs du pancréas/génétique , Tumeurs du pancréas/métabolisme , Isoformes de protéines , Cellules cancéreuses en culture
19.
J Cell Biol ; 144(2): 325-37, 1999 Jan 25.
Article de Anglais | MEDLINE | ID: mdl-9922458

RÉSUMÉ

Classical cell dissociation/reaggregation experiments with embryonic tissue and cultured cells have established that cellular cohesiveness, mediated by cell adhesion molecules, is important in determining the organization of cells within tissue and organs. We have employed N-CAM-deficient mice to determine whether N-CAM plays a functional role in the proper segregation of cells during the development of islets of Langerhans. In N-CAM-deficient mice the normal localization of glucagon-producing alpha cells in the periphery of pancreatic islets is lost, resulting in a more randomized cell distribution. In contrast to the expected reduction of cell-cell adhesion in N-CAM-deficient mice, a significant increase in the clustering of cadherins, F-actin, and cell-cell junctions is observed suggesting enhanced cadherin-mediated adhesion in the absence of proper N-CAM function. These data together with the polarized distribution of islet cell nuclei and Na+/K+-ATPase indicate that islet cell polarity is also affected. Finally, degranulation of beta cells suggests that N-CAM is required for normal turnover of insulin-containing secretory granules. Taken together, our results confirm in vivo the hypothesis that a cell adhesion molecule, in this case N-CAM, is required for cell type segregation during organogenesis. Possible mechanisms underlying this phenomenon may include changes in cadherin-mediated adhesion and cell polarity.


Sujet(s)
Ilots pancréatiques/cytologie , Molécules d'adhérence cellulaire neurales/physiologie , Animaux , Cadhérines/biosynthèse , Cadhérines/génétique , Cellules épithéliales/cytologie , Expression des gènes , Cellules L (lignée cellulaire) , Souris , Souris de lignée C57BL , Souris knockout , Molécules d'adhérence cellulaire neurales/génétique
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