Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 147
Filtrar
1.
J Obstet Gynaecol ; 35(8): 788-92, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26082295

RESUMEN

This paper aims to determine if the 2003 International Society for the Study of Vulvovaginal Disease (ISSVD) terminology and classification of vulval pain is up-to-date, according to a current and widely accepted neurobiological pain classification, which divides pain into nociceptive, inflammatory and pathological pain with the latter subdivided into neuropathic and dysfunctional pain. Nociceptive pain is protective, adaptive, high-threshold pain provoked by noxious stimuli. Inflammatory pain is protective, adaptive, low-threshold pain associated with peripheral tissue damage and inflammation. Pathological pain is non-protective, maladaptive, low-threshold pain caused by structural damage to the nervous system (neuropathic pain) or by its abnormal function (dysfunctional pain). The 2003 ISSVD vulval pain classification should be revised in terms of current neurobiological pain information. Inflammatory vulval pain occurs as a result of specific infectious, inflammatory and neoplastic disorders. Neuropathic vulval pain arises following a specific neurological disorder, responsible for structural damage to the nervous system. Vulvodynia is dysfunctional vulval pain, caused by abnormal function of the nervous system itself.


Asunto(s)
Vulvodinia/diagnóstico , Femenino , Humanos , Neurobiología , Terminología como Asunto , Vulvodinia/clasificación
2.
J Obstet Gynaecol ; 34(4): 285-8, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24649846

RESUMEN

This paper aims to clarify the nature of the pain in provoked vestibulodynia (PV). It reviews published data about the nature of the pain in PV, employing a recent pain classification, which divides pain from a neurobiological perspective, into nociceptive, inflammatory and pathological pain, with the latter subdivided into neuropathic and dysfunctional pain. Nociceptive pain is high-threshold pain provoked by noxious stimuli; inflammatory pain is adaptive, low-threshold pain associated with peripheral tissue inflammation; pathological pain is maladaptive, low-threshold pain caused by structural damage to the nervous system (neuropathic) or by its abnormal function (dysfunctional). Most of the published data show that in PV, there is no active peripheral tissue inflammation. Similarly, no neural damage has been demonstrated. It is reasonable to consider PV as dysfunctional pain induced by exposure to acute physical or psychological precipitating events in the presence of an individual predisposition to produce or maintain abnormal central sensitisation.


Asunto(s)
Dolor/etiología , Vulvodinia/etiología , Femenino , Humanos
3.
Philos Trans A Math Phys Eng Sci ; 371(1997): 20110622, 2013 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-23858485

RESUMEN

We describe an analysis of cardiac and respiratory time series recorded from 189 subjects of both genders aged 16-90. By application of the synchrosqueezed wavelet transform, we extract the respiratory and cardiac frequencies and phases with better time resolution than is possible with the marked events procedure. By treating the heart and respiration as coupled oscillators, we then apply a method based on Bayesian inference to find the underlying coupling parameters and their time dependence, deriving from them measures such as synchronization, coupling directionality and the relative contributions of different mechanisms. We report a detailed analysis of the reconstructed cardiorespiratory coupling function, its time evolution and age dependence. We show that the direct and indirect respiratory modulations of the heart rate both decrease with age, and that the cardiorespiratory coupling becomes less stable and more time-variable.


Asunto(s)
Envejecimiento/fisiología , Relojes Biológicos/fisiología , Frecuencia Cardíaca/fisiología , Modelos Biológicos , Frecuencia Respiratoria/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Simulación por Computador , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
4.
J Dairy Sci ; 96(6): 3671-81, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23587392

RESUMEN

Somatic cell count (SCC) limits are a key component of national and international regulation for milk quality. As yet, very limited work has been published on SCC regulatory standards, including on the effect of different approaches to SCC data adjustment and interpretation. This study examines the effect of SCC data adjustment and interpretation, as outlined in current European Union (EU) legislation, on herd eligibility to supply raw milk for processing of dairy products for human consumption, using Irish data for illustration. The study used Irish milk-recording data as a proxy for bulk tank SCC (BTSCC) data, to calculate an unadjusted monthly SCC value for each herd during each month of participation. Subsequently, 4 data adjustments were applied, as outlined in EU and national legislation: seasonal adjustment; 3-mo rolling geometric average, without accounting for a break in the supply; 3-mo rolling geometric average, after accounting for a break in the supply; and seasonal adjustment and 3-mo rolling geometric average combined, after accounting for a break in the supply. Analyses were conducted to examine the effect, during the period from 2004 to 2010, of data adjustment on the percentage of herds with herd SCC >400,000 cells/mL. In all, 4 interpretation scenarios, incorporating different data adjustment combinations, were used to estimate herd eligibility (compliant, under warning, or suspended, as defined by legislation) to supply raw milk for processing. The 4 methods of data adjustment each led to a sizable reduction (6.7, 5.0, 5.3, and 11.1 percentage points, respectively, compared with the unadjusted data) in the percentage of herds exceeding a herd SCC of 400,000 cells/mL. Herd eligibility varied by interpretation scenarios, in particular those incorporating seasonal adjustment. The study provides new perspectives on the effect of data adjustment on herd SCC and of interpretation scenarios on herd eligibility. The results provide an illustrative, rather than definitive, picture of this effect, as national authorities use BTSCC data when determining herd eligibility, whereas this study was conducted using milk-recording data as a proxy. Some aspects of the primary EU legislation are unclear, which may lead to differences in interpretation and application. The potential impact of data adjustment and milk purchaser pricing on farm-level mastitis control in Ireland is considered.


Asunto(s)
Bovinos , Recuento de Células/veterinaria , Industria Lechera/legislación & jurisprudencia , Unión Europea , Manipulación de Alimentos/legislación & jurisprudencia , Leche/citología , Animales , Productos Lácteos , Femenino , Calidad de los Alimentos , Irlanda , Mastitis Bovina/prevención & control , Estaciones del Año
5.
Stress ; 11(2): 115-24, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18311600

RESUMEN

Exposure to an acute naturalistic stressor induces both psychological and physiological changes in humans. The two studies reported here explored the impact of exposure to an acute naturalistic stressor on state anxiety, working memory and HPA axis activation (salivary cortisol). In both experiments, ten healthy male participants were exposed to an acute naturalistic stressor, helicopter underwater evacuation training (HUET), and their physiological and behavioural responses before (first study) and after (second study) the stressor were compared to ten non-stressed controls. The results of both experiments showed that working memory performance was preserved during anticipation of an acute stressor, but impairments were observed immediately after stress exposure. Participants reported significantly higher state anxiety levels during anticipation and following stress exposure, whereas significant elevations in cortisol levels were only observed 25 min post exposure to stress, but not before or immediately after stress exposure. The results of both experiments demonstrated a dissociation between behavioural and biochemical measures and provided evidence for a dissociation of the effects of stress on cognitive and physiological measures depending on the time of testing, with cognitive impairments most evident following stress exposure.


Asunto(s)
Ansiedad/fisiopatología , Ansiedad/psicología , Hidrocortisona/análisis , Memoria a Corto Plazo/fisiología , Saliva/metabolismo , Estrés Psicológico/fisiopatología , Estrés Psicológico/psicología , Adulto , Aeronaves , Humanos , Sistema Hipotálamo-Hipofisario/fisiopatología , Masculino , Persona de Mediana Edad , Sistema Hipófiso-Suprarrenal/fisiopatología
6.
Brain Res ; 1152: 10-6, 2007 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-17433807

RESUMEN

The vesicular monoamine transporter type 2 (VMAT2) packages pre-synaptic monoamines into vesicles. Previously, we generated mice hypomorphic for the VMAT2 gene (Slc18a2), which results in a approximately 95% reduction in VMAT2 protein, disrupted vesicular storage, severe depletion of striatal dopamine and mice with moderate motor behaviour deficits. Dopamine released from mid-brain dopamine neurons acts on post-synaptic type 1 (D1) and 2 (D2) receptors located on striatal medium spiny neurons to initiate a signalling cascade that leads to altered transcription factor activity, gene expression and neuronal activity. We investigated striatal gene expression changes in VMAT2hypo mice by quantitative real-time PCR and in situ hybridisation. Despite unaltered expression of D1 and D2 dopamine receptors, there were dramatic alterations in striatal mRNAs encoding the neuropeptides substance P, dynorphin, enkephalin and cholecystokinin. The promoters of these genes are regulated by a combination of transcription factors that includes cAMP responsive element binding protein-1 (CREB) and c-Fos. Indeed, the changes in peptide mRNAs were associated with elevated expression of Creb1 and c-Fos. These data indicate that striatal dopamine depletion, as a consequence of deficient vesicular storage in this mouse, triggers a complex program of gene expression, consistent with this mouse being an excellent model of Parkinson's disease.


Asunto(s)
Cuerpo Estriado/metabolismo , Expresión Génica , Proteínas de Transporte Vesicular de Monoaminas/biosíntesis , Animales , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/biosíntesis , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Hibridación in Situ , Ratones , Ratones Endogámicos C57BL , Neuropéptidos/biosíntesis , Neuropéptidos/genética , Trastornos Parkinsonianos/genética , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas c-fos/biosíntesis , Proteínas Proto-Oncogénicas c-fos/genética , ARN Mensajero/biosíntesis , Receptores de Dopamina D1/biosíntesis , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/biosíntesis , Receptores de Dopamina D2/genética , Proteínas de Transporte Vesicular de Monoaminas/genética
7.
Br J Haematol ; 133(3): 345-52, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16643438

RESUMEN

The chemokine, stromal cell-derived factor-1 (SDF-1) is a crucial regulator of stem cell homing and tethering, and potentiation of this pathway in leukaemias may contribute to the pathogenesis of the disease. A key second messenger in SDF-1 signal/response coupling is phosphatidylinositol 3,4,5-triphosphate [PtdIns(3,4,5)P3]. SDF-1 elevated PtdIns(3,4,5)P3 levels markedly in the multipotent FDCP-mix stem cell line. Similarly, transfection with BCR/ABL or TEL/PDGFRbeta leukaemogenic tyrosine kinases chronically elevated PtdIns(3,4,5)P3 levels. However, whilst an SDF-1 chemotactic response was observed in TEL/PDGFRbeta-transfected cells, in BCR/ABL cells this was markedly decreased, which was not due to Ras-pathway activation. Thus, multipotent cells can respond to SDF-1, despite chronic increases in this second messenger indicating that a discrete pool of SDF-1-stimulated PtdIns(3,4,5)P3 production drives the chemotactic response. To discern the mechanism for the differential effects of these oncogenes we considered subcellular localisation. As TEL/PDGFRbeta has a cytosolic location whilst BCR/ABL associates with actin, we removed the actin-binding domain from BCR/ABL. We observed relocation of BCR/ABL to the cytosol and increased SDF-1 responses. We conclude that the localisation of BCR/ABL to the cytoskeleton is essential for effects on motility and moderating SDF-1 responses is not essential in tyrosine kinase-mediated leukaemic transformation.


Asunto(s)
Transformación Celular Neoplásica/metabolismo , Quimiocinas CXC/farmacología , Quimiotaxis/fisiología , Proteínas de Fusión bcr-abl/fisiología , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Actinas/metabolismo , Animales , Línea Celular , Quimiocina CXCL12 , Quimiotaxis/efectos de los fármacos , Citoesqueleto/metabolismo , Relación Dosis-Respuesta a Droga , Proteínas de Fusión bcr-abl/análisis , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/fisiología , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Ratones , Proteínas de Fusión Oncogénica/metabolismo , Fosfatidilinositol 3-Quinasas/fisiología , Fosfatos de Fosfatidilinositol/biosíntesis , Transducción de Señal , Transfección
8.
Br J Haematol ; 132(6): 774-83, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16487179

RESUMEN

Philadelphia chromosome-positive, chronic myeloid leukaemia (CML) stem and progenitor cells have a survival and growth advantage compared with their normal counterparts. The mechanisms through which the BCR/ABL protein tyrosine kinase (PTK) induces these effects and the important domains within this protein are not fully defined. The F- and G-actin binding region of the BCR/ABL C-terminus may be important in BCR/ABL-mediated events, and we have investigated this by expressing a C-terminus deletion mutant of the temperature-sensitive BCR/ABL PTK, in a haemopoietic progenitor cell line, which models the chronic phase of CML. The truncated BCR/ABL PTK displayed similar levels of PTK activity when compared with wild type and activation of second messenger formation (in the form of sn-1,2-diacylglycerol) remains intact. On fibronectin substrata, localisation of the protein to the periphery of the cell was, however, dependent on the C-terminus of BCR/ABL PTK. Deletion of the C-terminus reversed both BCR/ABL-mediated apoptotic suppression and drug resistance although the progenitor cells did retain a proliferative advantage at low concentrations of growth factor. These results demonstrated that the C-terminal actin-binding domain of BCR/ABL is important for some of BCR/ABL PTK-mediated leukaemogenic effects.


Asunto(s)
Actinas/genética , Proteínas de Fusión bcr-abl/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Proteínas Tirosina Quinasas/genética , Actinas/metabolismo , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/genética , Diferenciación Celular/genética , División Celular/genética , Línea Celular Tumoral , Clonación Molecular/métodos , Citarabina/farmacología , Resistencia a Antineoplásicos/genética , Técnica del Anticuerpo Fluorescente/métodos , Proteínas de Fusión bcr-abl/análisis , Humanos , Hidroxiurea/farmacología , Interleucina-3/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/enzimología , Leucemia Mielógena Crónica BCR-ABL Positiva/mortalidad , Lípidos/análisis , Modelos Biológicos , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/fisiología , Proteínas Tirosina Quinasas/metabolismo , Temperatura
9.
Br J Haematol ; 112(1): 212-5, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11167806

RESUMEN

The regulation of nutrient transport by both cytokines and oncogenes has been linked to haemopoietic cell survival. In this study, we found that activation of Bcr--Abl protein tyrosine kinase was associated with the stimulation of glucose transport in the multipotent haemopoietic cell line FDCP-mix, a cell model for chronic-phase chronic myeloid leukaemia (CML). Bcr--Abl upregulation of glucose transport was mediated by phosphatidylinositol-3-kinase. The observation that Bcr--Abl can regulate glucose transport in a CML cell model raises the possibility that glucose transport regulation may have a role to play in the aberrant survival of stem cells in the chronic phase of CML.


Asunto(s)
Desoxiglucosa/metabolismo , Proteínas de Fusión bcr-abl/metabolismo , Células Madre Hematopoyéticas/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Transporte Biológico , Muerte Celular , Línea Celular , Humanos , Fosfatidilinositol 3-Quinasas/metabolismo
10.
Arch Dermatol ; 137(2): 193-206, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11176692

RESUMEN

BACKGROUND: Recent studies suggest that paraneoplastic pemphigus (PNP) is a heterogeneous autoimmune syndrome involving several internal organs and that the pathophysiological mechanisms mediating cutaneous, mucosal, and internal lesions are not limited to autoantibodies targeting adhesion molecules. OBJECTIVE: To classify the diverse mucocutaneous and respiratory presentations of PNP and characterize the effectors of humoral and cellular autoimmunity mediating epithelial tissue damage. METHODS: We examined 3 patients manifesting the lichen planus pemphigoideslike subtype of PNP. A combination of standard immunohistochemical techniques, enzyme-linked immunosorbent assay with desmoglein (DSG) baculoproteins, and an immunoprecipitation assay were used to characterize effectors of humoral and cellular autoimmunity in patients with PNP and in neonatal wild-type and DSG3-knockout mice with PNP phenotype induced by passive transfer of patients' IgGs. RESULTS: In addition to the known "PNP antigenic complex," epithelial targets recognized by PNP antibodies included 240-, 150-, 130-, 95-, 80-, 70-, 66-, and 40/42-kd proteins but excluded DSG1 and DSG3. In addition to skin and the epithelium lining upper digestive and respiratory tract mucosa, deposits of autoantibodies were found in kidney, urinary bladder, and smooth as well as striated muscle. Autoreactive cellular cytotoxicity was mediated by CD8(+) cytotoxic T lymphocytes, CD56(+) natural killer cells, and CD68(+) monocytes/macrophages. Inducible nitric oxide synthase was visualized both in activated effectors of cellular cytotoxicity and their targets. Keratin 14-positive basal epithelial cells sloughed from the large airways and obstructed small airways. CONCLUSIONS: The paraneoplastic disease of epithelial adhesion known as PNP in fact represents only 1 manifestation of a heterogeneous autoimmune syndrome in which patients, in addition to small airway occlusion and deposition of autoantibodies in different organs, may display a spectrum of at least 5 different clinical and immunopathological mucocutaneous variants (ie, pemphiguslike, pemphigoidlike, erythema multiforme-like, graft-vs-host disease-like, and lichen planus-like). We suggest that the more encompassing term "paraneoplastic autoimmune multiorgan syndrome," or PAMS, be applied. The pathophysiological mechanisms of PAMS involve both humoral and cellular autoimmunity responses. Epithelial cell membrane antigens other than DSG1 or DSG3 are targeted by effectors of PAMS autoimmunity. Apoptosis of damaged basal cells mediates epithelial clefting, and respiratory failure results possibly from obstruction of small airways with sloughed epithelial cells.


Asunto(s)
Enfermedades Autoinmunes/inmunología , Síndromes Paraneoplásicos/inmunología , Pénfigo/inmunología , Animales , Antígenos de Superficie/inmunología , Autoanticuerpos/análisis , Autoanticuerpos/inmunología , Autoantígenos/inmunología , Enfermedades Autoinmunes/clasificación , Enfermedades Autoinmunes/patología , Autoinmunidad , Moléculas de Adhesión Celular/genética , Proteínas del Citoesqueleto/genética , Citotoxicidad Inmunológica , Desmogleína 1 , Desmogleína 3 , Desmogleínas , Desmoplaquinas , Ensayo de Inmunoadsorción Enzimática , Epitelio/inmunología , Humanos , Inmunización Pasiva , Inmunoglobulina G/inmunología , Inmunohistoquímica , Erupciones Liquenoides/clasificación , Erupciones Liquenoides/inmunología , Erupciones Liquenoides/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Persona de Mediana Edad , Síndromes Paraneoplásicos/clasificación , Síndromes Paraneoplásicos/patología , Pénfigo/clasificación , Pénfigo/patología , Fenotipo , Mucosa Respiratoria/inmunología , Mucosa Respiratoria/patología , Piel/inmunología , Piel/patología
14.
Oncogene ; 19(48): 5487-97, 2000 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-11114726

RESUMEN

Chronic myeloid leukaemia is a haemopoietic stem cell disorder, the hallmark of which is the expression of the Bcr-Abl Protein Tyrosine Kinase (PTK). We have previously reported that activation of a temperature sensitive Bcr-Abl PTK in the multipotent haemopoietic cell line FDCP-Mix for short periods resulted in subtle changes including, a transient suppression of apoptosis and no inhibition of differentiation. In contrast, activation of the Bcr-Abl PTK for 12 weeks results in cells that display a delay in differentiation at the early granulocyte stage. Flow cytometric analysis also indicates that the expression of cell surface differentiation markers and nuclear morphology are uncoupled. Furthermore, a significant number of the mature neutrophils display abnormal morphological features. Prolonged exposure to Bcr-Abl PTK results in interleukin-3 independent growth and decreased p53 protein levels. FDCP-Mix cells expressing a dominant negative p53 and p53null FDCP-Mix cells demonstrate that the reduction in p53 is causally related to the delay in development. Returning the cells to the restrictive temperature restores the p53 protein levels, the growth factor dependence and largely relieves the effects on development. We conclude that prolonged Bcr-Abl PTK activity within multipotent cells results in a reduction of p53 that drives a delayed and abnormal differentiation.


Asunto(s)
Proteínas de Fusión bcr-abl/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/enzimología , Células Mieloides/enzimología , Proteínas Tirosina Quinasas/metabolismo , Proteína p53 Supresora de Tumor/fisiología , Animales , Diferenciación Celular/fisiología , Silenciador del Gen , Genes p53 , Humanos , Interleucina-3/farmacología , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Ratones , Células Mieloides/citología , Temperatura , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/biosíntesis , Proteína p53 Supresora de Tumor/genética
15.
Hum Mutat ; 15(5): 410-7, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10790202

RESUMEN

Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle that manifests in response to anesthetic triggering agents. Central core disease (CCD) is a myopathy closely associated with MH. Both MH and CCD are primarily disorders of calcium regulation in skeletal muscle. The ryanodine receptor (RYR1) gene encodes the key channel which mediates calcium release in skeletal muscle during excitation-contraction coupling, and mutations in this gene are considered to account for susceptibility to MH (MHS) in more than 50% of cases and in the majority of CCD cases. To date, 22 missense mutations in the 15,117 bp coding region of the RYR1 cDNA have been found to segregate with the MHS trait, while a much smaller number of these mutations is associated with CCD. The majority of RYR1 mutations appear to be clustered in the N-terminal amino acid residues 35-614 (MH/CCD region 1) and the centrally located residues 2163-2458 (MH/CCD region 2). The only mutation identified outside of these regions to date is a single mutation associated with a severe form of CCD in the highly conserved C-terminus of the gene. All of the RYR1 mutations result in amino acid substitutions in the myoplasmic portion of the protein, with the exception of the mutation in the C-terminus, which resides in the lumenal/transmembrane region. Functional analysis shows that MHS and CCD mutations produce RYR1 abnormalities that alter the channel kinetics for calcium inactivation and make the channel hyper- and hyposensitive to activating and inactivating ligands, respectively. The likely deciding factors in determining whether a particular RYR1 mutation results in MHS alone or MHS and CCD are: sensitivity of the RYR1 mutant proteins to agonists; the level of abnormal channel-gating caused by the mutation; the consequential decrease in the size of the releasable calcium store and increase in resting concentration of calcium; and the level of compensation achieved by the muscle with respect to maintaining calcium homeostasis. From a diagnostic point of view, the ultimate goal of development of a simple non-invasive test for routine diagnosis of MHS remains elusive. Attainment of this goal will require further detailed molecular genetic investigations aimed at solving heterogeneity and discordance issues in MHS; new initiatives aimed at identifying modulating factors that influence the penetrance of clinical MH in MHS individuals; and detailed studies aimed at describing the full epidemiological picture of in vitro responses of muscle to agents used in diagnosis of MH susceptibility.


Asunto(s)
Hipertermia Maligna/genética , Mutación , Miopatía del Núcleo Central/genética , Canal Liberador de Calcio Receptor de Rianodina/genética , Sustitución de Aminoácidos , Exones , Humanos , Hipertermia Maligna/diagnóstico , Hipertermia Maligna/fisiopatología , Músculo Esquelético/fisiopatología , Mutación Missense , Miopatía del Núcleo Central/diagnóstico , Miopatía del Núcleo Central/fisiopatología , Polimorfismo Genético
16.
J Biol Chem ; 275(17): 13142-8, 2000 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-10777620

RESUMEN

Leukemogenic oncogenes, such as the Abelson protein-tyrosine kinases (PTK), disrupt the normal regulation of survival, proliferation, and differentiation in hemopoietic progenitor cells. In the absence of cytokines, hemopoietic progenitor cells die by apoptosis. Abl PTKs mediate suppression of this apoptotic response leading to aberrant survival. To investigate the mechanism of Abl PTK action, we have used an interleukin-3-dependent murine mast cell line that expresses a temperature-sensitive form of the v-ABL PTK, which is active at the permissive temperature of 32 degrees C and inactive at 39 degrees C. At the permissive temperature, these cells are resistant to apoptosis induced both by the withdrawal of the hemopoietic growth factor (interleukin-3) and the addition of cytotoxic drugs. We demonstrate that v-Abl associates with and stimulates activation of phosphatidylinositol 3-kinase (PI3K) and, crucially, that this activation results in enhanced cellular levels of the mass of the second messenger phosphatidylinositol-3,4,5-trisphosphate. Activation of PI3K leads to enhanced activity of PKB and increased levels of the anti-apoptotic protein Bcl-X(L). Transfection of cells with a dominant negative PKB reduces both the Abl-stimulated PKB activity and the survival effect conferred by activation of this oncogene. Thus, PI3K and PKB are required for the anti-apoptotic effects of Abl PTK.


Asunto(s)
Apoptosis , Fosfatidilinositol 3-Quinasas/fisiología , Proteínas Serina-Treonina Quinasas , Proteínas Tirosina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/fisiología , Animales , Línea Celular , Supervivencia Celular , Activación Enzimática , Immunoblotting , Isoenzimas , Ratones , Fosfatidilinositol 3-Quinasas/química , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas/química , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-akt , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Transducción de Señal , Temperatura , Factores de Tiempo , Transfección , Proteína bcl-X
18.
Proc Natl Acad Sci U S A ; 96(7): 4164-9, 1999 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-10097181

RESUMEN

Central core disease is a rare, nonprogressive myopathy that is characterized by hypotonia and proximal muscle weakness. In a large Mexican kindred with an unusually severe and highly penetrant form of the disorder, DNA sequencing identified an I4898T mutation in the C-terminal transmembrane/luminal region of the RyR1 protein that constitutes the skeletal muscle ryanodine receptor. All previously reported RYR1 mutations are located either in the cytoplasmic N terminus or in a central cytoplasmic region of the 5,038-aa protein. The I4898T mutation was introduced into a rabbit RYR1 cDNA and expressed in HEK-293 cells. The response of the mutant RyR1 Ca2+ channel to the agonists halothane and caffeine in a Ca2+ photometry assay was completely abolished. Coexpression of normal and mutant RYR1 cDNAs in a 1:1 ratio, however, produced RyR1 channels with normal halothane and caffeine sensitivities, but maximal levels of Ca2+ release were reduced by 67%. [3H]Ryanodine binding indicated that the heterozygous channel is activated by Ca2+ concentrations 4-fold lower than normal. Single-cell analysis of cotransfected cells showed a significantly increased resting cytoplasmic Ca2+ level and a significantly reduced luminal Ca2+ level. These data are indicative of a leaky channel, possibly caused by a reduction in the Ca2+ concentration required for channel activation. Comparison with two other coexpressed mutant/normal channels suggests that the I4898T mutation produces one of the most abnormal RyR1 channels yet investigated, and this level of abnormality is reflected in the severe and penetrant phenotype of affected central core disease individuals.


Asunto(s)
Miopatías Nemalínicas/genética , Mutación Puntual , Polimorfismo Genético , Canal Liberador de Calcio Receptor de Rianodina/genética , Canal Liberador de Calcio Receptor de Rianodina/fisiología , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Cafeína/farmacología , Calcio/metabolismo , Línea Celular , Mapeo Cromosómico , Clonación de Organismos , ADN Complementario , Femenino , Marcadores Genéticos , Genotipo , Halotano/farmacología , Humanos , Masculino , México , Mutagénesis Sitio-Dirigida , Miopatías Nemalínicas/fisiopatología , Linaje , Conejos , Proteínas Recombinantes/efectos de los fármacos , Proteínas Recombinantes/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/efectos de los fármacos , Transfección
19.
Arch Dermatol ; 134(8): 971-80, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9722727

RESUMEN

OBJECTIVES: To determine whether nondesmoglein (non-Dsg) autoantibodies are pathogenic and whether they recognize keratinocyte cholinergic receptors that control cell adhesion because antikeratinocyte autoimmunity in patients with pemphigus vulgaris is not limited to the development of autoantibodies to Dsg. DESIGN: To determine whether non-DSg autoantibodies are pathogenic, we sought to induce pemphigus in genetically engineered neonatal mice lacking Dsg 3 using pemphigus vulgaris IgGs that did not cross-react with Dsg 1. To determine whether pemphigus autoimmunity involves keratinocyte cholinergic receptors, the latter were separated from cell membranes of human keratinocytes, tagged with the covalent label [3H]propylbenzilylcholine mustard, and used as an antigen in a radioimmunoprecipitation assay of 34 pemphigus vulgaris and 6 pemphigus foliaceus serum samples. SETTING: The dermatologic clinics of the University of Minnesota, Minneapolis; the Mayo Clinic, Rochester, Minn; and the University of California-Davis Medical Center, Sacramento. PATIENTS: Serum samples were collected from 34 patients with pemphigus vulgaris and 6 patients with pemphigus foliaceus (aged 31-89 years) and from 7 age-similar patients of both sexes with nonpemphigus blistering or the following immune-mediated conditions: pemphigoid gestation, bullous drug eruption, lupus erythematosus, erythema nodosum, urticaria, acute contact dermatitis, and skin ulcers. MAIN OUTCOME MEASURES: Clinical, laboratory, and histopathologic findings. RESULTS: Extensive skin blistering accompanied by the Nikolsky sign and suprabasilar acantholysis was induced in the Dsg3null mice that received pemphigus, but not normal human IgGs. In the radioimmunoprecipitation assays for reactivity with cholinergic receptors, the mean radioactivity precipitated by pemphigus serum samples significantly exceeded both normal- and disease-control levels (P = .001-.02). The mean individual levels of radioactivity precipitated by 34 pemphigus vulgaris and pemphigus foliaceus serum samples (85%) exceeded control values by a mean of approximately 2.6 times. CONCLUSIONS: Autoantibodies to keratinocyte cell-surface molecules other than Dsg 1 and Dsg 3 can induce clinical features of pemphigus vulgaris. Patients with pemphigus vulgaris and those with pemphigus foliaceus develop IgG antibodies that precipitate radiolabeled cholinergic receptors. Because these receptors control keratinocyte adhesion and motility, their inactivation by autoantibodies may elicit intracellular signals that cause disassembly of desmosomes, leading to acantholysis and blistering.


Asunto(s)
Autoanticuerpos/biosíntesis , Moléculas de Adhesión Celular/inmunología , Queratinocitos/inmunología , Pénfigo/inmunología , Receptores Colinérgicos/inmunología , Acantólisis/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Estudios de Casos y Controles , Adhesión Celular/inmunología , Proteínas del Citoesqueleto/inmunología , Dermatitis por Contacto/inmunología , Desmoplaquinas , Desmosomas/inmunología , Eritema Nudoso/inmunología , Femenino , Ingeniería Genética , Humanos , Inmunoglobulina G/inmunología , Lupus Eritematoso Sistémico/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos , Persona de Mediana Edad , Penfigoide Ampolloso/inmunología , Pénfigo/clasificación , Enfermedades Cutáneas Vesiculoampollosas/inmunología , Úlcera Cutánea/inmunología , Urticaria/inmunología
20.
Oncogene ; 17(5): 667-72, 1998 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-9704934

RESUMEN

Chronic myeloid leukaemia (CML) is a clonal disorder of the pluripotent haemopoietic stem cell, the hallmark of which is the constitutively activated Bcr-Abl protein tyrosine kinase. During the initial chronic phase of CML the primitive multipotent leukaemic progenitor cells remain growth factor dependent and are capable of producing terminally differentiated cells. Although the available evidence suggests that Bcr-Abl directly affects signalling pathways involved in controlling the development of primitive haemopoietic progenitors the identification of the specific biological consequences of Bcr-Abl activity in these progenitors has been hampered by the lack of suitable systems modelling CML. By transfecting the multipotent haemopoietic cell line FDCP-Mix with a temperature sensitive mutant of Bcr-Abl we have developed the first working model that mirrors the chronic phase of CML. FDCP-Mix cells expressing Bcr-Abl tyrosine kinase activity remain growth factor dependent and retain their ability to differentiate. Normal neutrophilic cells are formed in response to G-CSF and GM-CSF. In addition, the transfected FDCP-Mix cells grown at the permissive temperature for Bcr-Abl tyrosine kinase activity display enhanced survival and proliferation in low concentrations of growth factor. These findings are consistent with the initial subtle changes seen in CML progenitor cells during the chronic phase and confirm that Bcr-Abl effects are context specific, i.e. they depend on the origin and developmental potential of the transfected cells. This questions the significance of studies in non-haemopoietic and differentiation blocked haemopoietic cells.


Asunto(s)
Línea Celular , Proteínas de Fusión bcr-abl/biosíntesis , Células Madre Hematopoyéticas/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva , División Celular , Supervivencia Celular , Proteínas de Fusión bcr-abl/genética , Células Madre Hematopoyéticas/patología , Humanos , Modelos Biológicos , Temperatura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA