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1.
Oncogene ; 36(45): 6348-6358, 2017 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-28806393

RESUMEN

Pediatric low-grade gliomas (PLGGs) are commonly associated with BRAF gene fusions that aberrantly activate the mitogen-activated protein kinase (MAPK) signaling pathway. This has led to PLGG clinical trials utilizing RAF- and MAPK pathway-targeted therapeutics. Whole-genome profiling of PLGGs has also identified rare gene fusions involving another RAF isoform, CRAF/RAF1, in PLGGs and cancers occuring in adults. Whereas BRAF fusions primarily dysregulate MAPK signaling, the CRAF fusions QKI-RAF1 and SRGAP3-RAF1 aberrantly activate both the MAPK and phosphoinositide-3 kinase/mammalian target of rapamycin (PI3K/mTOR) signaling pathways. Although ATP-competitive, first-generation RAF inhibitors (vemurafenib/PLX4720, RAFi) cause paradoxical activation of the MAPK pathway in BRAF-fusion tumors, inhibition can be achieved with 'paradox breaker' RAFi, such as PLX8394. Here we report that, unlike BRAF fusions, CRAF fusions are unresponsive to both generations of RAFi, vemurafenib and PLX8394, highlighting a distinct responsiveness of CRAF fusions to clinically relevant RAFi. Whereas PLX8394 decreased BRAF-fusion dimerization, CRAF-fusion dimerization is unaffected primarily because of robust protein-protein interactions mediated by the N-terminal non-kinase fusion partner, such as QKI. The pan-RAF dimer inhibitor, LY3009120, could suppress CRAF-fusion oncogenicity by inhibiting dimer-mediated signaling. In addition, as CRAF fusions activate both the MAPK and PI3K/mTOR signaling pathways, we identify combinatorial inhibition of the MAPK/mTOR pathway as a potential therapeutic strategy for CRAF-fusion-driven tumors. Overall, we define a mechanistic distinction between PLGG-associated BRAF- and CRAF/RAF1 fusions in response to RAFi, highlighting the importance of molecularly classifying PLGG patients for targeted therapy. Furthermore, our study uncovers an important contribution of the non-kinase fusion partner to oncogenesis and potential therapeutic strategies against PLGG-associated CRAF fusions and possibly pan-cancer CRAF fusions.


Asunto(s)
Glioma/tratamiento farmacológico , Glioma/genética , Proteínas Proto-Oncogénicas c-raf/genética , Adolescente , Animales , Línea Celular Tumoral , Niño , Preescolar , Dimerización , Glioma/patología , Humanos , Ratones , Células 3T3 NIH , Clasificación del Tumor , Fusión de Oncogenes , Proteínas Proto-Oncogénicas c-raf/metabolismo , Transducción de Señal , Transfección
2.
Nature ; 545(7653): 199-202, 2017 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-28492251

RESUMEN

The Jovian moon Io hosts the most powerful persistently active volcano in the Solar System, Loki Patera. The interior of this volcanic, caldera-like feature is composed of a warm, dark floor covering 21,500 square kilometres surrounding a much cooler central 'island'. The temperature gradient seen across areas of the patera indicates a systematic resurfacing process, which has been seen to occur typically every one to three years since the 1980s. Analysis of past data has indicated that the resurfacing progressed around the patera in an anti-clockwise direction at a rate of one to two kilometres per day, and that it is caused either by episodic eruptions that emplace voluminous lava flows or by a cyclically overturning lava lake contained within the patera. However, spacecraft and telescope observations have been unable to map the emission from the entire patera floor at sufficient spatial resolution to establish the physical processes at play. Here we report temperature and lava cooling age maps of the entire patera floor at a spatial sampling of about two kilometres, derived from ground-based interferometric imaging of thermal emission from Loki Patera obtained on 8 March 2015 ut as the limb of Europa occulted Io. Our results indicate that Loki Patera is resurfaced by a multi-phase process in which two waves propagate and converge around the central island. The different velocities and start times of the waves indicate a non-uniformity in the lava gas content and/or crust bulk density across the patera.

3.
Am J Transplant ; 15(5): 1376-83, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25777987

RESUMEN

On approach to addressing the continual shortage of organ donors is to encourage people to join a state donor registry. Joining the registry saves time and assures family members that organ donation is what their loved one would want. However, fewer than half of adults have taken this step. We tested a brief, web-based training program for department of motor vehicles (DMV) staff that educates them about organ and tissue donation and also models the correct way to interact with customers. The intervention was developed with extensive input and active participation from DMV staff. After a small-scale pilot test, all DMV offices across the state of West Virginia (WV) were randomized to receive the training or serve as a comparison group. The results showed that customers of DMV staff who had received the training were 7.5% more likely to register as organ donors. A conservative estimate is that this generates approximately 800 additional donor designations per month. An important aspect of web-based training is that once it has been deployed, it can continue to be used without incurring additional cost; the state of WV currently requires all new employees to complete the training program. This type of training can be adopted nationwide.


Asunto(s)
Capacitación en Servicio , Sistema de Registros , Donantes de Tejidos/provisión & distribución , Obtención de Tejidos y Órganos/métodos , Adulto , Femenino , Humanos , Internet , Masculino , Vehículos a Motor , West Virginia
4.
J Dent Res ; 90(11): 1352-7, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21917602

RESUMEN

Patients with amelogenesis imperfecta (AI) have defective enamel; therefore, bonded restorations of patients with AI have variable success rates. To distinguish which cases of AI may have good clinical outcomes with bonded materials, we evaluated etching characteristics and bond strength of enamel in mouse models, comparing wild-type (WT) with those having mutations in amelogenin (Amelx) and matrix metalloproteinase-20 (Mmp20), which mimic 2 forms of human AI. Etched enamel surfaces were compared for roughness by scanning electron microscopy (SEM) images. Bonding was compared through shear bond strength (SBS) studies with 2 different systems (etch-and-rinse and self-etch). Etched enamel surfaces of incisors from Amelx knock-out (AmelxKO) mice appeared randomly organized and non-uniform compared with WT. Etching of Mmp20KO surfaces left little enamel, and the etching pattern was indistinguishable from unetched surfaces. SBS results were significantly different when AmelxKO and Mmp20KO enamel surfaces were compared. A significant increase in SBS was measured for all samples when the self-etch system was compared with the etch-and-rinse system. We have developed a novel system for testing shear bond strength of mouse incisors with AI variants, and analysis of these data may have important clinical implications for the treatment of patients with AI.


Asunto(s)
Amelogénesis Imperfecta/fisiopatología , Amelogenina/deficiencia , Recubrimiento Dental Adhesivo , Esmalte Dental/patología , Modelos Animales de Enfermedad , Metaloproteinasa 20 de la Matriz/deficiencia , Grabado Ácido Dental , Amelogénesis Imperfecta/genética , Amelogenina/fisiología , Animales , Esmalte Dental/metabolismo , Análisis del Estrés Dental , Metaloproteinasa 20 de la Matriz/fisiología , Ratones , Ratones Noqueados , Resistencia al Corte , Propiedades de Superficie
5.
Cell Tissue Bank ; 12(3): 219-31, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20589432

RESUMEN

Over 70,000 DBS devices have been implanted worldwide; however, there remains a paucity of well-characterized post-mortem DBS brains available to researchers. We propose that the overall understanding of DBS can be improved through the establishment of a Deep Brain Stimulation-Brain Tissue Network (DBS-BTN), which will further our understanding of DBS and brain function. The objectives of the tissue bank are twofold: (a) to provide a complete (clinical, imaging and pathological) database for DBS brain tissue samples, and (b) to make available DBS tissue samples to researchers, which will help our understanding of disease and underlying brain circuitry. Standard operating procedures for processing DBS brains were developed as part of the pilot project. Complete data files were created for individual patients and included demographic information, clinical information, imaging data, pathology, and DBS lead locations/settings. 19 DBS brains were collected from 11 geographically dispersed centers from across the U.S. The average age at the time of death was 69.3 years (51-92, with a standard deviation or SD of 10.13). The male:female ratio was almost 3:1. Average post-mortem interval from death to brain collection was 10.6 h (SD of 7.17). The DBS targets included: subthalamic nucleus, globus pallidus interna, and ventralis intermedius nucleus of the thalamus. In 16.7% of cases the clinical diagnosis failed to match the pathological diagnosis. We provide neuropathological findings from the cohort, and perilead responses to DBS. One of the most important observations made in this pilot study was the missing data, which was approximately 25% of all available data fields. Preliminary results demonstrated the feasibility and utility of creating a National DBS-BTN resource for the scientific community. We plan to improve our techniques to remedy omitted clinical/research data, and expand the Network to include a larger donor pool. We will enhance sample preparation to facilitate advanced molecular studies and progenitor cell retrieval.


Asunto(s)
Encéfalo/patología , Estimulación Encefálica Profunda , Enfermedad de Parkinson/patología , Enfermedad de Parkinson/terapia , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto
6.
J Surg Educ ; 65(6): 494-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19059183

RESUMEN

BACKGROUND: Much has been written about the influences of Accreditation Council for Graduate Medical Education (ACGME) work restrictions, the litigious climate in American medicine, and the proliferation of subspecialty fellowships on general surgery training. Few previous studies have addressed general surgical residents' perceptions of surgical training on a national level. METHODS: A 38-question Institutional Review Board-approved survey was sent via e-mail to the program directors at all ACGME-approved general surgical training programs for distribution to categorical general surgery residents. Voluntary responses to statements focusing on job satisfaction, quality of life, and the influences of operative experience, work hours, fellows, physician extenders, as well as faculty and administration on resident training were solicited. RESULTS: Overall, 997 responses were received from residents of all clinical levels from 40 states. Most respondents were from university-based programs (79%) with a broad representation of program sizes (mean of 6 graduates per year; range 2 to 11). Residents believe that they will be prepared to enter clinical practice at the conclusion of their training (86%), that the duration of surgical training is adequate (85%), and that they are exposed to sufficient case volume and complexity (85% and 84%, respectively). Only 360 respondents (36%) believe that they are financially compensated appropriately. Although most respondents support the ACGME work-hour restrictions (70%), far fewer feel that they improve their training or patient care (46.6% and 46.8%, respectively). Most respondents are proud to be surgical residents (88%), view surgery as a rewarding profession (87%), and would choose surgery as a profession again (77%). CONCLUSIONS: Surgical residents are positive regarding the quality of their training and life, although they feel poorly compensated for their work. Most residents intend to pursue fellowship training. Survey responses were consistent irrespective of gender, ethnicity, and program type.


Asunto(s)
Cirugía General/educación , Internado y Residencia , Satisfacción en el Trabajo , Humanos , Internet , Calidad de Vida , Salarios y Beneficios , Encuestas y Cuestionarios , Estados Unidos , Carga de Trabajo
7.
Science ; 302(5653): 2118-20, 2003 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-14684821

RESUMEN

Approximately 80% of the maize genome comprises highly repetitive sequences interspersed with single-copy, gene-rich sequences, and standard genome sequencing strategies are not readily adaptable to this type of genome. Methodologies that enrich for genic sequences might more rapidly generate useful results from complex genomes. Equivalent numbers of clones from maize selected by techniques called methylation filtering and High C0t selection were sequenced to generate approximately 200,000 reads (approximately 132 megabases), which were assembled into contigs. Combination of the two techniques resulted in a sixfold reduction in the effective genome size and a fourfold increase in the gene identification rate in comparison to a nonenriched library.


Asunto(s)
Genes de Plantas , Genoma de Planta , Análisis de Secuencia de ADN/métodos , Zea mays/genética , Cromosomas de las Plantas/genética , Clonación Molecular , Biología Computacional , Mapeo Contig , Metilación de ADN , ADN de Plantas/genética , Bases de Datos de Ácidos Nucleicos , Etiquetas de Secuencia Expresada , Dosificación de Gen , Biblioteca de Genes , Datos de Secuencia Molecular , Secuencias Repetitivas de Ácidos Nucleicos , Retroelementos , Alineación de Secuencia , Transcripción Genética
8.
Proc Natl Acad Sci U S A ; 98(5): 2425-30, 2001 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-11226255

RESUMEN

FKBP12, the 12-kDa FK506-binding protein, is a ubiquitous abundant protein that acts as a receptor for the immunosuppressant drug FK506, binds tightly to intracellular calcium release channels and to the transforming growth factor beta (TGF-beta) type I receptor. We now demonstrate that cells from FKBP12-deficient (FKBP12(-/-)) mice manifest cell cycle arrest in G(1) phase and that these cells can be rescued by FKBP12 transfection. This arrest is mediated by marked augmentation of p21(WAF1/CIP1) levels, which cannot be further augmented by TGF-beta1. The p21 up-regulation and cell cycle arrest derive from the overactivity of TGF-beta receptor signaling, which is normally inhibited by FKBP12. Cell cycle arrest is prevented by transfection with a dominant-negative TGF-beta receptor construct. TGF-beta receptor signaling to gene expression can be mediated by SMAD, p38, and ERK/MAP kinase (extracellular signal-regulated kinase/mitogen-activated protein kinase) pathways. SMAD signaling is down-regulated in FKBP12(-/-) cells. Inhibition of ERK/MAP kinase fails to affect p21 up-regulation. By contrast, activated phosphorylated p38 is markedly augmented in FKBP12(-/-) cells and the p21 up-regulation is prevented by an inhibitor of p38. Thus, FKBP12 is a physiologic regulator of cell cycle acting by normally down-regulating TGF-beta receptor signaling.


Asunto(s)
Ciclo Celular/fisiología , Proteína 1A de Unión a Tacrolimus/fisiología , Animales , Secuencia de Bases , Células Cultivadas , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Ciclinas/metabolismo , Cartilla de ADN , Ratones , Ratones Noqueados , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Reacción en Cadena de la Polimerasa , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Transducción de Señal , Proteína 1A de Unión a Tacrolimus/genética , Regulación hacia Arriba , Proteínas Quinasas p38 Activadas por Mitógenos
9.
Eur J Immunol ; 30(7): 2101-11, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10940900

RESUMEN

The role of TGF-beta1 in the regulation of T cell responses has been perplexing, possibly because it is dependent on the type of T cell being regulated and its cytokine microenvironment. In the present study, we demonstrate that TGF-beta1 has a profound inhibitory effect on naive CD4+ T cell undergoing differentiation under defined neutral, Th1 and Th2 priming conditions. In addition, we show that if CD4+ T cells are primed in the presence of TGF-beta1, they exhibit reduced secondary anti-CD3/anti-CD28-induced and antigen-specific immune responses (even when TGF-beta is absent during the secondary response), which is not due to reduced expression of co-stimulatory molecules or to inadequate IL-2 production. Finally, with respect to the effect of TGF-beta on fully differentiated antigen-specific memory CD4+ T cells, we demonstrate that while antigen-specific activation and cytokine secretion by memory Th1 T cells is inhibited by TGF-beta1, such inhibition is associated with partial down-regulation of IL-12 receptor beta2 chain expression. In contrast, memory Th2 T cells are not subject to TGF-beta1 -mediated suppression. In summary, these studies reveal that TGF-beta1 is a powerful negative regulator of the primary immune response of CD4+ T cells, but only Th1 T cells are subject to such regulation after the memory stage of T cell differentiation has been reached. Thus, these studies define the potential regulatory role of TGF-beta1 in Th1 and Th2 T cell-mediated autoimmunity.


Asunto(s)
Memoria Inmunológica/inmunología , Células TH1/inmunología , Células Th2/inmunología , Factor de Crecimiento Transformador beta/inmunología , Animales , Apoptosis , Diferenciación Celular , Células Cultivadas , Proteínas de Unión al ADN/metabolismo , Interferón gamma/biosíntesis , Interleucina-2/administración & dosificación , Interleucina-2/inmunología , Interleucina-4/biosíntesis , Ratones , Ratones Endogámicos BALB C , Ovalbúmina/inmunología , Fragmentos de Péptidos/inmunología , Fosforilación , Receptores de Interleucina/metabolismo , Receptores de Interleucina-12 , Factor de Transcripción STAT4 , Factor de Transcripción STAT6 , Células TH1/citología , Células TH1/efectos de los fármacos , Células Th2/citología , Células Th2/efectos de los fármacos , Transactivadores/metabolismo
10.
J Neurochem ; 73(4): 1539-48, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10501199

RESUMEN

The role of the GABA(A) receptor beta3 subunit in determining acute cocaine sensitivity and behavioral sensitization to repeated cocaine was measured in mice missing both (-/-), one (+/-), or neither (+/+) allele of the beta3 gene. Locomotor stimulation induced by one cocaine injection (20 mg/kg, i.p.) was found to be greater in -/- mice compared with +/+ mice, whereas cocaine-induced behaviors were intermediate in +/- mice. Amphetamine did not cause greater locomotor responses in -/- mice, suggesting that the increased sensitivity of -/- mice to cocaine does not generalize to other psychomotor stimulants. GABA-stimulated chloride uptake was 51% lower in striatum of -/- mice compared with +/+ mice, but only 27% lower in cortex. After 14 daily cocaine injections, the behavioral response to cocaine was increased in +/+ and +/- mice, but was not increased further in -/- mice. Additionally, repeated cocaine exposure decreased striatal GABA(A) receptor function in +/+ and +/- mice. In -/- mice, GABA(A) receptor function was not decreased any further by repeated cocaine injections. Thus, alterations in the beta3 subunit may be responsible for determining the behavioral responses induced by acute and repeated cocaine treatment, as well as mediating the neurochemical adaptation that occurs during sensitization to repeated cocaine.


Asunto(s)
Cocaína/farmacología , Actividad Motora/fisiología , Receptores de GABA-A/fisiología , Anfetamina/farmacología , Animales , Corteza Cerebral/metabolismo , Cloruros/metabolismo , Genotipo , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos , Ratones Noqueados , Actividad Motora/efectos de los fármacos , Receptores de GABA-A/deficiencia , Receptores de GABA-A/genética
11.
Appl Opt ; 38(8): 1384-7, 1999 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-18305757

RESUMEN

An expression for the polarized emissivity of a material is obtained with the Stokes vector-Mueller matrix polarization formalism. The result obtained is that thermally emitted radiance might have a circular polarization component. In addition, the emissivity depends only on the reflectance matrix.

12.
Psychiatry Res ; 77(3): 147-58, 1998 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-9707297

RESUMEN

This study examined neuropsychological performance across the menstrual cycle in women with varying levels of premenstrual symptomatology. Following a 2-month period of prospective symptom documentation, there were 19 women who met DSM-IV criteria for Premenstrual Dysphoric Disorder (PMDD group) and 18 women with mild to moderate symptoms. Neuropsychological functioning was evaluated at the late follicular (pre-ovulatory) and late luteal (premenstrual) phases across the domains of psychomotor speed, attention, and verbal learning and memory. Repeated measures analysis of variance yielded significant group x phase differences on the psychomotor index, with women in the PMDD group demonstrating significant psychomotor slowing in the late luteal phase. This psychomotor slowing was subtle, however, and scores remained within the normal range across testing sessions. No group or phase differences were found on indices of attention or verbal learning and memory. These results suggest that with the exception of subtle psychomotor slowing in the late follicular relative to the late luteal phase, there is no discernible difference in cognitive functioning between women with and without PMDD.


Asunto(s)
Ciclo Menstrual/psicología , Pruebas Neuropsicológicas , Síndrome Premenstrual/psicología , Desempeño Psicomotor , Tiempo de Reacción , Adulto , Atención , Femenino , Humanos , Fase Luteínica/psicología , Recuerdo Mental , Síndrome Premenstrual/diagnóstico , Aprendizaje Verbal
13.
Brain Res Mol Brain Res ; 57(2): 310-20, 1998 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-9675429

RESUMEN

The functional status of striatal GABAA receptors appears to be inversely related to the magnitude of cocaine-induced behaviors. Exposure of striatum to antisense oligodeoxynucleotides (ASODNs) targeted to the mRNAs for the alpha 2 and the beta 3 subunits of the GABAA receptor should decrease expression of receptor proteins and therefore might be expected to increase cocaine sensitivity. ASODNs, scrambled ODNs or saline were injected into right lateral ventricle of rats and behavioral responses to cocaine were tested 18-20 h after treatment. Animals injected separately with alpha 2 or beta 3 ASODNs exhibited increased behavioral sensitivity to cocaine compared to rats injected with saline or scrambled ODNs including performing more 360 degrees turns to the left than to the right. There was significantly less GABA-stimulated Cl uptake in right striatum compared to left striatum of ASODN-treated rats with no significant difference between sides in control animals. Specific binding to benzodiazepine and convulsant sites on the GABAA receptor was not selectively altered by ASODN treatment. Combined alpha 2 beta 3 ASODN treatment did not affect either cocaine sensitivity or GABAA receptor function. There was no difference between the density of Nissl stained cells in the left and right edges of striatum in control or ASODN-treated rats indicating the absence of significant neurotoxic effects of the ASODN treatment. Injection of fluorescein-conjugated ASODNs indicated that ASODN is present in striatum at times during which behavioral and neurochemical indices of GABA receptor function are decreased. Thus, the functional status of GABAA receptors in striatum may be involved in determining cocaine sensitivity.


Asunto(s)
Cocaína/farmacología , Cuerpo Estriado/efectos de los fármacos , Inhibidores de Captación de Dopamina/farmacología , Antagonistas de Receptores de GABA-A , Oligonucleótidos Antisentido/farmacología , Ácido gamma-Aminobutírico/farmacología , Análisis de Varianza , Animales , Cloruros/metabolismo , Cuerpo Estriado/metabolismo , Semivida , Masculino , Ratas , Ratas Sprague-Dawley , Estimulación Química , Transmisión Sináptica/efectos de los fármacos
14.
Plant Cell ; 9(6): 947-55, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9212468

RESUMEN

Persistent oscillation in constant conditions is a defining characteristic of circadian rhythms. However, in plants transferred into extended dark conditions, circadian rhythms in mRNA abundance commonly damp in amplitude over two or three cycles to a steady state level of relatively constant, low mRNA abundance. In Arabidopsis, catalase CAT3 mRNA oscillations damp rapidly in extended dark conditions, but unlike catalase CAT2 and the chlorophyll a/b binding protein gene CAB, in which the circadian oscillations damp to low steady state mRNA abundance, CAT3 mRNA oscillations damp to high steady state levels of mRNA abundance. Mutational disruption of either phytochrome- or cryptochrome-mediated light perception prevents damping of the oscillations in CAT3 mRNA abundance and reveals strong circadian oscillations that persist for multiple cycles in extended dark conditions. Damping of CAT3 mRNA oscillations specifically requires phytochrome A but not phytochrome B and also requires the cryptochrome1 blue light receptor. Therefore, we conclude that synergistic signaling mediated through both phytochrome A and cryptochrome1 is required for damping of circadian CAT3 mRNA oscillations in extended dark conditions.


Asunto(s)
Arabidopsis/enzimología , Catalasa/biosíntesis , Ritmo Circadiano , Proteínas de Drosophila , Proteínas del Ojo , Flavoproteínas/fisiología , Células Fotorreceptoras de Invertebrados , Fitocromo/fisiología , Proteínas de Plantas/fisiología , Transducción de Señal , Arabidopsis/genética , Proteínas de Arabidopsis , Catalasa/genética , Criptocromos , Oscuridad , Sinergismo Farmacológico , Regulación Enzimológica de la Expresión Génica , Luz , Fitocromo A , ARN Mensajero/metabolismo , Receptores Acoplados a Proteínas G
15.
Int Arch Allergy Immunol ; 112(3): 270-8, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9066514

RESUMEN

OBJECTIVE: Allergic bronchopulmonary aspergillosis, a disabling hypersensitivity lung disease, results from inhalation of Aspergillus fumigatus antigens present in contaminated environments. A murine model has been developed to understand the immune mechanism involved in allergic bronchopulmonary aspergillosis. We have investigated the immunoregulatory role of different physical forms of A.fumigatus antigens, such as A.fumigatus spores, soluble antigens. and soluble antigen coupled inert particles, in the model. METHODS: BALB/c mice were exposed to soluble A.fumigatus antigens, spores, or inert particles of comparable size to the spores coupled with A.fumigatus soluble antigens. Antibody and eosinophil response, pulmonary pathology, and cytokine expressions were studied. RESULTS: Peripheral blood eosinophilia and pulmonary inflammation with influx of eosinophils into the lung was detected more in animals exposed to particulate antigens than in those exposed to soluble antigen. However, the total serum IgE and Aspergillus-specific IgG levels showed only a slight increase in the former groups as opposed to elevated levels in animals exposed to soluble antigen. The cytokine expression in in vitro antigen stimulated spleen cells showed a typical Th2 pattern in all antigen-exposed animals. IL-5 mRNA could be detected in the spleen cells cultured with antigen from all groups of antigen-exposed animals. CONCLUSION: Particulate A.fumigatus antigens induced eosinophilia in mice prior to the elevation of serum IgE levels. This pattern of IgE and eosinophilia is reversed with the soluble antigen exposure in this model.


Asunto(s)
Antígenos Fúngicos/fisiología , Eosinofilia/inmunología , Animales , Anticuerpos Antifúngicos/inmunología , Especificidad de Anticuerpos , Aspergilosis Broncopulmonar Alérgica/complicaciones , Aspergillus fumigatus/inmunología , Médula Ósea/enzimología , Células de la Médula Ósea , Citocinas/genética , Citocinas/metabolismo , Eosinofilia/complicaciones , Eosinófilos/enzimología , Femenino , Inmunoglobulina E/biosíntesis , Interferón gamma/fisiología , Interleucina-4/fisiología , Interleucina-5/fisiología , Pulmón/patología , Ratones , Ratones Endogámicos BALB C , Peroxidasa/análisis , ARN Mensajero/metabolismo , Bazo/citología , Esporas Fúngicas/inmunología
16.
J Biol Rhythms ; 12(1): 47-64, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9104690

RESUMEN

The aim of this study was to replicate and extend previous work in which the authors observed lower, shorter, and advanced nocturnal melatonin secretion patterns in premenstrually depressed patients compared to those in healthy control women. The authors also sought to test the hypothesis that the therapeutic effect of bright light in patients was associated with corrective effects on the phase, duration, and amplitude of melatonin rhythms. In 21 subjects with premenstrual dysphoric disorder (PMDD) and 11 normal control (NC) subjects, the authors measured the circadian profile of melatonin during follicular and luteal menstrual cycle phases and after 1 week of light therapy administered daily, in a randomized crossover design. During three separate luteal phases, the treatments were either (1) bright (> 2,500 lux) white morning (AM; 06:30 to 08:30 h), (2) bright white evening (PM; 19:00 to 21:00 h), or (3) dim (< 10 lux) red evening light (RED). In PMDD subjects, during the luteal phase compared to the follicular menstrual cycle phase, melatonin onset time was delayed, duration was compressed, and area under the curve, amplitude, and mean levels were decreased. In NC subjects, melatonin rhythms did not change significantly during the menstrual cycle. After AM light in PMDD subjects, onset and offset times were advanced and both duration and midpoint concentration were decreased as compared to RED light. After PM light in PMDD subjects, onset and offset times were delayed, midpoint concentration was increased, and duration was decreased as compared to RED light. By contrast, after light therapy in NC subjects, duration did not change; onset, offset, and midpoint concentration changed as they did in PMDD subjects. When the magnitude of advance and delay phase shifts in onset versus offset time with AM, PM, or RED light were compared, the authors found that in PMDD subjects light shifted offset time more than onset time and that AM light had a greater effect on shifting melatonin offset time (measured the following night in RED light), whereas PM light had a greater effect in shifting melatonin onset time. These findings replicate the authors' previous observation that nocturnal melatonin concentrations are decreased in women with PMDD and suggest specific effects of light therapy on melatonin circadian rhythms that are associated with mood changes in patient versus control groups. The differential changes in onset and offset times during the menstrual cycle, and in response to AM and PM bright light compared with RED light, support a two-oscillator (complex) model of melatonin regulation in humans.


Asunto(s)
Ritmo Circadiano/fisiología , Melatonina/sangre , Ciclo Menstrual/fisiología , Fototerapia , Síndrome Premenstrual/fisiopatología , Síndrome Premenstrual/terapia , Adulto , Afecto/fisiología , Estudios Cruzados , Estrógenos/sangre , Femenino , Humanos , Ciclo Menstrual/psicología , Síndrome Premenstrual/sangre , Progesterona/sangre , Radioinmunoensayo
18.
Peptides ; 17(2): 183-90, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8801519

RESUMEN

Relevant allergens from Aspergillus fumigatus associated with allergic bronchopulmonary aspergillosis (ABPA) have been cloned and expressed. The pathogenesis of ABPA probably depends on specific cytokines and immunoglobulins secreted by lymphocytes on stimulation with different epitopes of those allergens. In the present study, we synthesized peptides of 12-16 amino acids from the sequence of Asp fI and compared their immunological responses in four mice strains (BALB/c, C57BL/6, AKR, and CBA). Of the five peptides studied for their cytokine profile, one showed a clear Th1, whereas another showed a Th2 response. The remaining three peptides varied in their immunoreactivity. The results suggest that a number of epitopes of diverse activities are present in individual molecules and may be involved in the pathogenesis of ABPA through differential cytokine secretions.


Asunto(s)
Alérgenos , Aspergillus fumigatus/inmunología , Citocinas/biosíntesis , Proteínas Fúngicas/inmunología , Ribonucleasas/inmunología , Células TH1/inmunología , Células Th2/inmunología , Secuencia de Aminoácidos , Animales , Anticuerpos Antifúngicos/biosíntesis , Antígenos de Plantas , Inmunoglobulina A/inmunología , Interferón gamma/biosíntesis , Interleucina-10/biosíntesis , Interleucina-2/biosíntesis , Interleucina-4/biosíntesis , Interleucina-5/biosíntesis , Ratones , Ratones Endogámicos AKR , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Datos de Secuencia Molecular
19.
J Clin Invest ; 96(5): 2142-51, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7593599

RESUMEN

The colon, unlike most organs, is normally exposed to high concentrations of ammonia, a weak base which exerts profound and diverse biological effects on mammalian cells. The impact of ammonia on intestinal cell function is largely unknown despite its concentration of 4-70 mM in the colonic lumen. The human intestinal epithelial cell line T84 was used to model electrogenic Cl- secretion, the transport event which hydrates mucosal surfaces and accounts for secretory diarrhea. Transepithelial transport and isotopic flux analysis indicated that physiologically-relevant concentrations of ammonia (as NH4Cl) markedly inhibit cyclic nucleotide-regulated Cl- secretion but not the response to the Ca2+ agonist carbachol. Inhibition by ammonia was 25-fold more potent with basolateral compared to apical exposure. Ion substitution indicated that the effect of NH4Cl was not due to altered cation composition or membrane potential. The site of action of ammonia is distal to cAMP generation and is not due simply to cytoplasmic alkalization. The results support a novel role for ammonia as an inhibitory modulator of intestinal epithelial Cl- secretion. Secretory responsiveness may be dampened in pathological conditions associated with increased mucosal permeability due to enhanced access of lumenal ammonia to the basolateral epithelial compartment.


Asunto(s)
Amoníaco/farmacología , Cloruros/metabolismo , AMP Cíclico/metabolismo , Mucosa Intestinal/fisiología , Línea Celular , Polaridad Celular , Impedancia Eléctrica , Humanos , Mucosa Intestinal/citología , Transporte Iónico/efectos de los fármacos , L-Lactato Deshidrogenasa/metabolismo
20.
J Allergy Clin Immunol ; 95(5 Pt 1): 950-4, 1995 May.
Artículo en Inglés | MEDLINE | ID: mdl-7751515

RESUMEN

BACKGROUND: Latex hypersensitivity has been described in discrete populations including health care workers and children with spina bifida (SB). OBJECTIVE: This study was designed to determine whether the SB population is a unique neuroimmunologic group manifesting this sensitivity. METHODS: Four groups of subjects were studied. These included: 36 patients with SB with or without clinical evidence of latex hypersensitivity, 50 patients with spinal cord injury (SCI), and 10 patients with cerebrovascular accidents (CVAs), all of whom were questioned regarding contact with and possible clinical allergic reactions to latex. Ten healthy control subjects were also studied. We used a latex sap extract, previously shown to react with latex-specific IgE in a biotin-avidin ELISA, to determine latex-specific IgE antibody titers and to compare the groups. RESULTS: Responses to questionnaires indicated that neither the patients with SCI nor the patients with CVA had histories suggestive of latex hypersensitivity. In contrast, 72% of the SB population had histories of clinical latex allergy. Comparisons of latex contact among the SB, SCI, CVA, and control groups revealed that the SB and SCI groups had similar latex exposure, whereas the other groups had less exposure. Both the SB and SCI groups had an average of two surgical procedures per year, which was greater than the average for the other groups. Comparisons of IgE latex antibody titers among the groups indicated that only the SB group had significant levels. The mean optical density values for each group were: 0.299 +/- 0.177 for patients with SB and positive skin prick test results, 0.072 +/- 0.066 for patients with SB and negative skin prick test results, 0.098 +/- 0.005 in patients with SCI, 0.073 +/- 0.038 in patients with CVA, and 0.053 +/- 0.034 in control subjects. The percentages of positive latex IgE antibody detection were 72% for SB, 4% for SCI, 0% for CVA, and 0% for control groups. CONCLUSIONS: The results suggest that the SB population is unique in demonstrating IgE responses to latex contact, which may be due to increased latex exposure or altered neuroimmunologic interactions.


Asunto(s)
Anafilaxia/etiología , Látex/efectos adversos , Disrafia Espinal/complicaciones , Procedimientos Quirúrgicos Operativos/efectos adversos , Adolescente , Anciano , Anafilaxia/inmunología , Especificidad de Anticuerpos , Trastornos Cerebrovasculares/complicaciones , Niño , Preescolar , Femenino , Humanos , Inmunoglobulina E/sangre , Lactante , Masculino , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos , Traumatismos de la Médula Espinal/complicaciones , Disrafia Espinal/cirugía
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