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1.
Nature ; 557(7706): 526-529, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29736017

RESUMO

Broad absorption signatures from alkali metals, such as the sodium (Na I) and potassium (K I) resonance doublets, have long been predicted in the optical atmospheric spectra of cloud-free irradiated gas giant exoplanets1-3. However, observations have revealed only the narrow cores of these features rather than the full pressure-broadened profiles4-6. Cloud and haze opacity at the day-night planetary terminator are considered to be responsible for obscuring the absorption-line wings, which hinders constraints on absolute atmospheric abundances7-9. Here we report an optical transmission spectrum for the 'hot Saturn' exoplanet WASP-96b obtained with the Very Large Telescope, which exhibits the complete pressure-broadened profile of the sodium absorption feature. The spectrum is in excellent agreement with cloud-free, solar-abundance models assuming chemical equilibrium. We are able to measure a precise, absolute sodium abundance of logεNa = [Formula: see text], and use it as a proxy for the planet's atmospheric metallicity relative to the solar value (Zp/Zʘ = [Formula: see text]). This result is consistent with the mass-metallicity trend observed for Solar System planets and exoplanets10-12.

2.
Rev. esp. anestesiol. reanim ; 62(5): 245-252, mayo 2015. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-140135

RESUMO

Objetivo: Detectar anomalías faringolaríngeas no valoradas habitualmente en la evaluación de la vía aérea difícil mediante la realización en el preoperatorio de una laringoscopia indirecta con el laringoscopio rígido e investigar su influencia en la predicción de la dificultad de intubación traqueal (DIT). Métodos: Estudio observacional prospectivo en 300 pacientes consecutivos sometidos a intervenciones quirúrgicas programadas bajo anestesia general. Además de evaluar los predictores demográficos y clínicos comunes de la vía aérea difícil, les fue practicada en el preoperatorio una laringoscopia indirecta con el laringoscopio rígido para diagnosticar las anomalías faringolaríngeas. Después, bajo anestesia general y laringoscopia directa comprobamos en qué pacientes existía DIT. Se investigó la asociación de todas las variables anteriores con la DIT, se confeccionó un modelo de regresión logística con fines predictivos y su poder de discriminación se consiguió valorando el área bajo la curva ROC obtenida. Resultados: Se contabilizaron 46 anomalías: 31 alteraciones de la epiglotis (22 epiglotis abarquilladas, 9 epiglotis flácidas o hipertrofiadas), 6 amígdalas linguales hipertróficas, 3 tumores en la vía aérea superior y 6 alteraciones de la lengua. Se encontró DIT en 14 casos (4,66%). El modelo elaborado y sus coeficientes para confeccionarlo fueron: f(x) = 1,322 + (2,173 distancia tiromentoniana < 6,5 cm) + (1,813 epiglotis abarquillada) - (1,310* cm abertura boca). El poder global de discriminación era 0,83 (IC 95%: 0,70-0,95). Conclusiones: La laringoscopia indirecta permitió el diagnóstico de las anomalías faringolaríngeas, y de ellas la epiglotis abarquillada fue una de las variables incluidas en el modelo de regresión logística (AU)


Objective: To determine the pharyngolaryngeal anomalies not usually included in the evaluation of difficult airway, in order to investigate the influence of these anomalies in the prediction of difficult intubation. To do this, indirect laryngoscopy with a 70° rigid laryngoscope was performed on all patients during the preoperative period. Methods: This is an observational, prospective study on 300 consecutive patients who were scheduled for endotracheal intubation under general anesthesia. In addition to assessing the airway in the preoperative period by demographic and clinical predictors of difficult airway, rigid indirect laryngoscopy was performed to diagnose pharyngolaryngeal anomalies. Later, under general anesthesia and direct laryngoscopy it was checked to see if there was difficulty in intubating the larynx, and its association with all previous variables was investigated. A logistic regression model for prediction purposes was developed, and its power of discrimination was achieved by assessing the area under the curve. Results: During the examination by indirect laryngoscopy 46 anomalies were found, which were as follows: 31 abnormalities of the epiglottis (22 omega epiglottis, 9 flaccid or hypertrophic epiglottis); 6 findings of hypertrophic lingual tonsils, 3 cases of upper airway tumors, and 6 patients with tongue disorders. Intubation difficulty was found in 14 cases (4.66%). The regression model found, and its coefficients to develop it were: f(x) = 1.322 + (2.173 thyromental distance < 6.5 cm) + (1.813 omega epiglottis) - (1.310*cm opening mouth). Global power of discrimination was 0.83, with a 95% confidence interval from 0.709 to 0.952). Conclusion: Indirect laryngoscopy allowed pharyngolaryngeal anomalies to be diagnosed, including omega epiglottis, which was one of the variables included in the logistic regression model (AU)


Assuntos
Humanos , Anestésicos/administração & dosagem , Anestesia Endotraqueal/métodos , Intubação Intratraqueal , Faringe/anormalidades , Laringe/anormalidades , Fatores de Risco , Manuseio das Vias Aéreas/métodos , Laringoscopia/métodos , Epiglote/lesões
3.
Rev Esp Anestesiol Reanim ; 62(5): 245-52, 2015 May.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-25129415

RESUMO

OBJECTIVE: To determine the pharyngolaryngeal anomalies not usually included in the evaluation of difficult airway, in order to investigate the influence of these anomalies in the prediction of difficult intubation. To do this, indirect laryngoscopy with a 70° rigid laryngoscope was performed on all patients during the preoperative period. METHODS: This is an observational, prospective study on 300 consecutive patients who were scheduled for endotracheal intubation under general anesthesia. In addition to assessing the airway in the preoperative period by demographic and clinical predictors of difficult airway, rigid indirect laryngoscopy was performed to diagnose pharyngolaryngeal anomalies. Later, under general anesthesia and direct laryngoscopy it was checked to see if there was difficulty in intubating the larynx, and its association with all previous variables was investigated. A logistic regression model for prediction purposes was developed, and its power of discrimination was achieved by assessing the area under the curve. RESULTS: During the examination by indirect laryngoscopy 46 anomalies were found, which were as follows: 31 abnormalities of the epiglottis (22 omega epiglottis, 9 flaccid or hypertrophic epiglottis); 6 findings of hypertrophic lingual tonsils, 3 cases of upper airway tumors, and 6 patients with tongue disorders. Intubation difficulty was found in 14 cases (4.66%). The regression model found, and its coefficients to develop it were: f(x)=1.322+(2.173 thyromental distance <6.5 cm)+(1.813 omega epiglottis)-(1.310*cm opening mouth). Global power of discrimination was 0.83, with a 95% confidence interval from 0.709 to 0.952). CONCLUSION: Indirect laryngoscopy allowed pharyngolaryngeal anomalies to be diagnosed, including omega epiglottis, which was one of the variables included in the logistic regression model.


Assuntos
Manuseio das Vias Aéreas/métodos , Obstrução das Vias Respiratórias/diagnóstico , Laringoscopia/métodos , Laringe/anormalidades , Faringe/anormalidades , Adulto , Epiglote/anormalidades , Feminino , Humanos , Hipertrofia , Intubação Intratraqueal , Masculino , Pessoa de Meia-Idade , Tonsila Palatina/patologia , Cuidados Pré-Operatórios , Estudos Prospectivos , Neoplasias do Sistema Respiratório/complicações , Neoplasias do Sistema Respiratório/diagnóstico , Língua/anormalidades
4.
Biochim Biophys Acta ; 1838(6): 1560-7, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24211605

RESUMO

Ion channel conformational changes within the lipid membrane are a key requirement to control ion passage. Thus, it seems reasonable to assume that lipid composition should modulate ion channel function. There is increasing evidence that this implicates not just an indirect consequence of the lipid influence on the physical properties of the membrane, but also specific binding of selected lipids to certain protein domains. The result is that channel function and its consequences on excitability, contractility, intracellular signaling or any other process mediated by such channel proteins, could be subjected to modulation by membrane lipids. From this it follows that development, age, diet or diseases that alter lipid composition should also have an influence on those cellular properties. The wealth of data on the non-annular lipid binding sites in potassium channel from Streptomyces lividans (KcsA) makes this protein a good model to study the modulation of ion channel structure and function by lipids. The fact that this protein is able to assemble into clusters through the same non-annular sites, resulting in large changes in channel activity, makes these sites even more interesting as a potential target to develop lead compounds able to disrupt such interactions and hopefully, to modulate ion channel function. This Article is Part of a Special Issue Entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.


Assuntos
Íons/metabolismo , Bicamadas Lipídicas/metabolismo , Lipídeos de Membrana/metabolismo , Canais de Potássio/metabolismo , Streptomyces lividans/metabolismo , Sítios de Ligação
5.
Braz. j. med. biol. res ; 45(8): 763-770, Aug. 2012. ilus
Artigo em Inglês | LILACS | ID: lil-643652

RESUMO

The striatum, the largest component of the basal ganglia, is usually subdivided into associative, motor and limbic components. However, the electrophysiological interactions between these three subsystems during behavior remain largely unknown. We hypothesized that the striatum might be particularly active during exploratory behavior, which is presumably associated with increased attention. We investigated the modulation of local field potentials (LFPs) in the striatum during attentive wakefulness in freely moving rats. To this end, we implanted microelectrodes into different parts of the striatum of Wistar rats, as well as into the motor, associative and limbic cortices. We then used electromyograms to identify motor activity and analyzed the instantaneous frequency, power spectra and partial directed coherence during exploratory behavior. We observed fine modulation in the theta frequency range of striatal LFPs in 92.5 ± 2.5% of all epochs of exploratory behavior. Concomitantly, the theta power spectrum increased in all striatal channels (P < 0.001), and coherence analysis revealed strong connectivity (coefficients >0.7) between the primary motor cortex and the rostral part of the caudatoputamen nucleus, as well as among all striatal channels (P < 0.001). Conclusively, we observed a pattern of strong theta band activation in the entire striatum during attentive wakefulness, as well as a strong coherence between the motor cortex and the entire striatum. We suggest that this activation reflects the integration of motor, cognitive and limbic systems during attentive wakefulness.


Assuntos
Animais , Feminino , Masculino , Ratos , Comportamento Animal/fisiologia , Corpo Estriado/fisiologia , Potenciais Evocados/fisiologia , Comportamento Exploratório/fisiologia , Ritmo Teta/fisiologia , Vigília/fisiologia , Eletrodos Implantados , Microeletrodos , Ratos Wistar
6.
Braz J Med Biol Res ; 45(8): 763-70, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22735177

RESUMO

The striatum, the largest component of the basal ganglia, is usually subdivided into associative, motor and limbic components. However, the electrophysiological interactions between these three subsystems during behavior remain largely unknown. We hypothesized that the striatum might be particularly active during exploratory behavior, which is presumably associated with increased attention. We investigated the modulation of local field potentials (LFPs) in the striatum during attentive wakefulness in freely moving rats. To this end, we implanted microelectrodes into different parts of the striatum of Wistar rats, as well as into the motor, associative and limbic cortices. We then used electromyograms to identify motor activity and analyzed the instantaneous frequency, power spectra and partial directed coherence during exploratory behavior. We observed fine modulation in the theta frequency range of striatal LFPs in 92.5 ± 2.5% of all epochs of exploratory behavior. Concomitantly, the theta power spectrum increased in all striatal channels (P < 0.001), and coherence analysis revealed strong connectivity (coefficients >0.7) between the primary motor cortex and the rostral part of the caudatoputamen nucleus, as well as among all striatal channels (P < 0.001). Conclusively, we observed a pattern of strong theta band activation in the entire striatum during attentive wakefulness, as well as a strong coherence between the motor cortex and the entire striatum. We suggest that this activation reflects the integration of motor, cognitive and limbic systems during attentive wakefulness.


Assuntos
Comportamento Animal/fisiologia , Corpo Estriado/fisiologia , Potenciais Evocados/fisiologia , Comportamento Exploratório/fisiologia , Ritmo Teta/fisiologia , Vigília/fisiologia , Animais , Eletrodos Implantados , Feminino , Masculino , Microeletrodos , Ratos , Ratos Wistar
9.
Biochemistry ; 49(25): 5397-404, 2010 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-20481584

RESUMO

KcsA, a homotetrameric potassium channel from prokaryotes, contains noncovalently bound lipids appearing in the X-ray crystallographic structure of the protein. The binding sites for such high-affinity lipids are referred to as "nonannular" sites, correspond to intersubunit protein domains, and bind preferentially anionic phospholipids. Here we used a thermal denaturation assay and detergent-phospholipid mixed micelles containing KcsA to study the effects of different phospholipids on protein stability. We found that anionic phospholipids stabilize greatly the tetrameric protein against irreversible, heat-induced unfolding and dissociation into subunits. This occurs in a phospholipid concentration-dependent manner, and phosphatidic acid species with acyl chain lengths ranging 14 to 18 carbon atoms are more efficient than similar phosphatidylglycerols in protecting the protein. A docking model of the KcsA-phospholipid complex suggests that the increased protein stability originates from the intersubunit nature of the binding sites and, thus, interaction of the phospholipid with such sites holds together adjacent subunits within the tetrameric protein. We also found that simpler amphiphiles, such as alkyl sulfates longer than 10 carbon atoms, also increase the protein stability to the same extent as anionic phospholipids, although at higher concentrations than the latter. Modeling the interaction of these simpler amphiphiles with KcsA and comparing it with that of anionic phospholipids serve to delineate the features of a hydrophobic pocket in the nonannular sites. Such pocket is predicted to comprise residues from the M2 transmembrane segment of a subunit and from the pore helix of the adjacent subunit and seems most relevant to protein stabilization.


Assuntos
Proteínas de Bactérias/metabolismo , Metabolismo dos Lipídeos , Canais de Potássio/metabolismo , Proteínas de Bactérias/química , Sítios de Ligação , Cristalografia por Raios X , Eletroforese em Gel de Poliacrilamida , Modelos Moleculares , Canais de Potássio/química , Conformação Proteica , Desnaturação Proteica , Espectrometria de Fluorescência
10.
Rev Esp Anestesiol Reanim ; 57(2): 91-4, 2010 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-20337000

RESUMO

Indirect inspection of the airway using a 70 degrees rigid laryngoscope plus a flexible nasal fiberoptic scope can provide additional information when the anesthesiologist foresees that airway management will be difficult. These devices are useful for detecting structural abnormalities, they can be attached to the same visualization system, and they do not require topical anesthesia or sedation of the patient. We report on 3 patients diagnosed with difficult airway. Inspection with a rigid laryngoscope during the preanesthetic assessment visit revealed abnormalities that prevented visualization of the glottis. In the first case, the epiglottis was absent, as it had been removed with a surrounding tumor; in the second and third cases, an epiglottic deformity and hypertrophy of the base of the tongue were found. A flexible nasal fiberoptic scope gave an unobstructed view of the glottis in these cases, making it easier to choose an intubation method.


Assuntos
Obstrução das Vias Respiratórias/diagnóstico , Tecnologia de Fibra Óptica/instrumentação , Laringoscópios , Otolaringologia/instrumentação , Cuidados Pré-Operatórios/métodos , Idoso , Obstrução das Vias Respiratórias/etiologia , Biópsia , Epiglote/patologia , Epiglote/cirurgia , Feminino , Humanos , Hipertrofia , Intubação Intratraqueal , Masculino , Pessoa de Meia-Idade , Sobrepeso/complicações , Neoplasias Faríngeas/cirurgia , Complicações Pós-Operatórias/patologia , Seio Piriforme/patologia , Compressão da Medula Espinal/cirurgia , Língua/patologia , Língua/cirurgia , Vitrectomia
11.
Rev. esp. anestesiol. reanim ; 57(2): 91-94, feb. 2010. ilus
Artigo em Espanhol | IBECS | ID: ibc-78831

RESUMO

La exploración de los pacientes con criterios de dificultaden el manejo de la vía aérea puede ser ampliadacon la realización de una laringoscopia indirecta utilizandoel laringoscopio rígido de 70º y el nasofibroscopioflexible. Son útiles para detectar anomalías estructurales,se acoplan al mismo sistema de visualización y noprecisan anestesia tópica ni sedación de los pacientes.Presentamos 3 pacientes diagnosticados de vía aéreadifícil, a los que se les realizó en la consulta de valoraciónpreanestésica una laringoscopia con el laringoscopiorígido. Se observó en el primero la falta de epiglotis,en el segundo una deformidad epiglótica y en el tercerouna hipertrofia de la base de la lengua, anormalidadesque impedían la visión de la glotis. Se les practicó unalaringoscopia con el nasofibroscopio flexible que permitióobservar la glotis sin obstáculos. La visión completade la vía aérea facilitó la elección del método de intubación(AU)


Indirect inspection of the airway using a 70° rigidlaryngoscope plus a flexible nasal fiberoptic scope canprovide additional information when the anesthesiologistforesees that airway management will be difficult. Thesedevices are useful for detecting structural abnormalities,they can be attached to the same visualization system, andthey do not require topical anesthesia or sedation of thepatient. We report on 3 patients diagnosed with difficultairway. Inspection with a rigid laryngoscope during thepreanesthetic assessment visit revealed abnormalities thatprevented visualization of the glottis. In the first case, theepiglottis was absent, as it had been removed with asurrounding tumor; in the second and third cases, anepiglottic deformity and hypertrophy of the base of thetongue were found. A flexible nasal fiberoptic scope gavean unobstructed view of the glottis in these cases, makingit easier to choose an intubation method(AU)


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Laringoscópios , Epiglote/anormalidades , Laringoscopia , Anestesia Geral , Fatores de Risco , Intubação/instrumentação , Intubação , Laringoscópios/classificação , Laringoscópios/tendências
12.
Bioinformatics ; 25(18): 2418-24, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19602529

RESUMO

MOTIVATION: Most of the structures and functions of proteome globular domains are yet unknown. We can use high-resolution structures from different modular domains in combination with automatic protein design algorithms to predict genome-wide potential interactions of a protein. ADAN database and related web tools are online resources for the predictive analysis of ligand-domain complexes. ADAN database is a collection of different modular protein domains (SH2, SH3, PDZ, WW, etc.). It contains 3505 entries with extensive structural and functional information available, manually integrated, curated and annotated with cross-references to other databases, biochemical and thermodynamical data, simplified coordinate files, sequence files and alignments. Prediadan, a subset of ADAN database, offers position-specific scoring matrices for protein-protein interactions, calculated by FoldX, and predictions of optimum ligands and putative binding partners. Users can also scan a query sequence against selected matrices, or improve a ligand-domain interaction. AVAILABILITY: ADAN is accessible at http://adan-embl.ibmc.umh.es/ or http://adan.crg.es/.


Assuntos
Motivos de Aminoácidos , Proteínas/química , Proteínas/metabolismo , Software , Algoritmos , Sítios de Ligação , Biologia Computacional/métodos , Bases de Dados de Proteínas , Mapeamento de Interação de Proteínas , Estrutura Terciária de Proteína , Análise de Sequência de Proteína
14.
J Membr Biol ; 223(3): 161-72, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18791833

RESUMO

The transient receptor potential vanilloid subtype 1 (TRPV1) is a member of the TRP family gated by vanilloids, heat, and protons. Structurally, TRPV1 subunits have a modular architecture underlying different functionalities, namely stimuli recognition, channel gating, ion selectivity, subunit oligomerization, and regulation by intracellular signaling molecules. Considering modular organization and recent structural information in the ion channel field, we have modeled a full-length TRPV1 by assembly of its major modules: the cytosolic N-terminal, C-terminal, and membrane-spanning region. For N-terminal, we used the ankyrin repeat structure fused with the N-end segment. The membrane domain was modeled with the structure of the eukaryotic, voltage-gated Kv1.2 K+ channel. The C-terminus was cast using the coordinates of HCN channels. The extensive structure-function data available for TRPV1 was used to validate the models in terms of the location of molecular determinants of function in the structure. Additionally, the current information allowed the modeling of the vanilloid receptor in the closed and desensitized states. The closed state shows the N-terminal module highly exposed and accessible to adenosine triphosphate and the C-terminal accessible to phosphoinositides. In contrast, the desensitized state depicts the N-terminal and C-terminal modules close together, compatible with an interaction mediated by Ca2+ -calmodulin complex. These models identify potential previously unrecognized intra- and interdomain interactions that may play an important functional role. Although the molecular models should be taken with caution, they provide a helpful tool that yields testable hypothesis that further our understanding on ion channels work in terms of underlying protein structure.


Assuntos
Simulação por Computador , Modelos Moleculares , Canais de Cátion TRPV/química , Canais de Cátion TRPV/metabolismo , Sequência de Aminoácidos , Animais , Membrana Celular/química , Membrana Celular/genética , Membrana Celular/metabolismo , Citosol/química , Citosol/metabolismo , Humanos , Canal de Potássio Kv1.2/química , Canal de Potássio Kv1.2/genética , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Estrutura Terciária de Proteína/genética , Ratos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Canais de Cátion TRPV/genética
15.
Biochemistry ; 43(47): 14924-31, 2004 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-15554699

RESUMO

KcsA is a prokaryotic potassium channel formed by the assembly of four identical subunits around a central aqueous pore. Although the high-resolution X-ray structure of the transmembrane portion of KcsA is known [Doyle, D. A., Morais, C. J., Pfuetzner, R. A., Kuo, A., Gulbis, J. M., Cohen, S. L., Chait, B. T., and MacKinnon, R. (1998) Science 280, 69-77], the identification of the molecular determinant(s) involved in promoting subunit tetramerization remains to be determined. Here, C-terminal deletion channel mutants, KcsA Delta125-160 and Delta120-160, as well as 1-125 KcsA obtained from chymotrypsin cleavage of full-length 1-160 KcsA, have been used to evaluate the role of the C-terminal segment on the stability and tetrameric assembly of the channel protein. We found that the lack of the cytoplasmic C-terminal domain of KcsA, and most critically the 120-124 sequence stretch, impairs tetrameric assembly of channel subunits in a heterologous E. coli expression system. Molecular modeling of KcsA predicts that, indeed, such sequence stretch provides intersubunit interaction sites by hydrogen bonding to amino acid residues in N- and C-terminal segments of adjacent subunits. However, once the KcsA tetramer is assembled, its remarkable in vitro stability to detergent or to heat-induced dissociation into subunits is not greatly influenced by whether the entire C-terminal domain continues being part of the protein. Finally and most interestingly, it is observed that, even in the absence of the C-terminal domain involved in tetramerization, reconstitution into membrane lipids promotes in vitro KcsA tetramerization very efficiently, an event which is likely mediated by allowing proper hydrophobic interactions involving intramembrane protein domains.


Assuntos
Proteínas de Bactérias/química , Metabolismo dos Lipídeos , Canais de Potássio/química , Estrutura Terciária de Proteína , Proteínas/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Quimotripsina/farmacologia , Clonagem Molecular , Detergentes/química , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Ligação de Hidrogênio , Hidrólise , Metionina/química , Modelos Moleculares , Dados de Sequência Molecular , Canais de Potássio/efeitos dos fármacos , Canais de Potássio/genética , Canais de Potássio/metabolismo , Proteínas/isolamento & purificação , Deleção de Sequência , Streptomyces lividans/química , Temperatura
16.
Bone Marrow Transplant ; 34(5): 419-23, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15286696

RESUMO

In an attempt to induce a graft-versus-myeloma effect, we administered donor lymphocyte infusions (DLI) after high-dose therapy with autologous stem cell transplant rescue to seven patients with refractory or relapsed multiple myeloma. High-dose therapy consisted of melphalan, idarubicin and etoposide (days -9 to -6) followed by autologous stem cell infusion on day 0. DLI (five of seven donors with two or three HLA antigens mismatched) were administered on days +1, +5 and +10 along with IL-2 (from day +1 through +12). Six of the seven patients developed acute graft-versus-host disease (GVHD), which resolved spontaneously, coincidentally with autologous hematopoietic reconstitution. One patient failed to engraft and received a second autologous graft. One patient died from complications of a pulmonary hemorrhage after experiencing GVHD. With a minimum follow-up of 38 months, five patients remain without disease progression in complete remission or with minimal residual disease. In this setting, DLI/IL-2 is biologically active resulting in GVHD. A graft-versus-myeloma effect is suggested by the improved outcome of our small cohort of high-risk patients. The use of partially mismatched related donors makes this approach potentially available to nearly all patients.


Assuntos
Transferência Adotiva , Transplante de Células-Tronco Hematopoéticas , Interleucina-2/administração & dosagem , Mieloma Múltiplo/terapia , Adulto , Terapia Combinada , Feminino , Seguimentos , Doença Enxerto-Hospedeiro/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/mortalidade , Fatores de Risco , Doadores de Tecidos
17.
Nature ; 422(6928): 143-6, 2003 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-12634780

RESUMO

The planet in the system HD209458 is the first one for which repeated transits across the stellar disk have been observed. Together with radial velocity measurements, this has led to a determination of the planet's radius and mass, confirming it to be a gas giant. But despite numerous searches for an atmospheric signature, only the dense lower atmosphere of HD209458b has been observed, through the detection of neutral sodium absorption. Here we report the detection of atomic hydrogen absorption in the stellar Lyman alpha line during three transits of HD209458b. An absorption of 15 +/- 4% (1sigma) is observed. Comparison with models shows that this absorption should take place beyond the Roche limit and therefore can be understood in terms of escaping hydrogen atoms.


Assuntos
Atmosfera/química , Hidrogênio/análise , Planetas , Gases/análise
18.
Nature ; 415(6875): 997-1000, 2002 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-11875560

RESUMO

Io leaves a magnetic footprint on Jupiter's upper atmosphere that appears as a spot of ultraviolet emission that remains fixed underneath Io as Jupiter rotates. The specific physical mechanisms responsible for generating those emissions are not well understood, but in general the spot seems to arise because of an electromagnetic interaction between Jupiter's magnetic field and the plasma surrounding Io, driving currents of around 1 million amperes down through Jupiter's ionosphere. The other galilean satellites may also leave footprints, and the presence or absence of such footprints should illuminate the underlying physical mechanism by revealing the strengths of the currents linking the satellites to Jupiter. Here we report persistent, faint, far-ultraviolet emission from the jovian footprints of Ganymede and Europa. We also show that Io's magnetic footprint extends well beyond the immediate vicinity of Io's flux-tube interaction with Jupiter, and much farther than predicted theoretically; the emission persists for several hours downstream. We infer from these data that Ganymede and Europa have persistent interactions with Jupiter's magnetic field despite their thin atmospheres.

19.
Int J Cosmet Sci ; 24(5): 303-10, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18498523

RESUMO

Botulinum neurotoxins (BoNTs) represent a revolution in cosmetic science because of their remarkable and long-lasting antiwrinkle activity. However, their high neurotoxicity seriously limits their use. Thus, there is a need to design and validate non-toxic molecules that mimic the action of BoNTs. The hexapeptide Ac-EEMQRR-NH(2) (coined Argireline) was identified as a result of a rational design programme. Noteworthy, skin topography analysis of an oil/water (O/W) emulsion containing 10% of the hexapeptide on healthy women volunteers reduced wrinkle depth up to 30% upon 30 days treatment. Analysis of the mechanism of action showed that Argireline significantly inhibited neurotransmitter release with a potency similar to that of BoNT A, although as expected, it displayed much lower efficacy than the neurotoxin. Inhibition of neurotransmitter release was due to the interference of the hexapeptide with the formation and/or stability of the protein complex that is required to drive Ca(2+)-dependent exocytosis, namely the vesicular fusion (known as SNARE) complex. Notably, this peptide did not exhibit in vivo oral toxicity nor primary irritation at high doses. Taken together, these findings demonstrate that Argireline is a non-toxic, antiwrinkle peptide that emulates the action of currently used BoNTs. Therefore, this hexapetide represents a biosafe alternative to BoNTs in cosmetics.

20.
Biochemistry ; 40(7): 2234-42, 2001 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-11329292

RESUMO

The catalytic domain of clostridial neurotoxins is a substrate of tyrosine-specific protein kinases. The functional role of tyrosine phosphorylation and also the number and location of its (their) phosphorylation site(s) are yet elusive. We have used the recombinant catalytic domain of botulinum neurotoxin E (BoNT E) to examine these issues. Bacterially expressed and purified BoNT E catalytic domain was fully active, and was phosphorylated in vitro by the tyrosine-specific kinase Src. Tyrosine phosphorylation of the catalytic domain increased the protein thermal stability without affecting its proteolytic activity. Covalent modification of the endopeptidase promoted a disorder-to-order transition, as evidenced by the 35% increment of the alpha-helical content, which resulted in a 4 degrees C increase of its denaturation temperature. Site-directed replacement of tyrosine at position 67 completely abolished phosphate incorporation by Src. Constitutively unphosphorylated endopeptidase mutants exhibited functional properties virtually identical to those displayed by the nonphosphorylated wild-type catalytic domain. These findings indicate the presence of a single phosphorylation site in the catalytic domain of clostridial neurotoxins, and that its covalent modification primarily modulates the protein thermostability.


Assuntos
Toxinas Botulínicas/metabolismo , Domínio Catalítico , Tirosina/metabolismo , Toxinas Botulínicas/biossíntese , Toxinas Botulínicas/genética , Toxinas Botulínicas/isolamento & purificação , Domínio Catalítico/genética , Dicroísmo Circular , Temperatura Alta , Mutagênese Sítio-Dirigida , Fragmentos de Peptídeos/biossíntese , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/isolamento & purificação , Fragmentos de Peptídeos/metabolismo , Fenilalanina/genética , Fosforilação , Desnaturação Proteica , Estrutura Secundária de Proteína/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Tirosina/genética , Quinases da Família src/metabolismo
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