124 resultados para KIR


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本学位论文共有5章。第一章报道白芍的化学成分及芍药苷的微生物转化研究成果;第二章报道天山雪莲的化学成分研究;第三章报道两面针的化学成分研究;第四章报道通关藤的化学成分研究成果;第五章概述了花椒属植物中最近十年报道的新化合物及药理研究情况。 在第1章的第一部分报道了白芍(Paeonia lactiflora Pall.)的化学成分。我们采用正、反相硅胶柱层析等各种分离方法,从白芍的干燥根中共分离出14个化合物,其中1个为新化合物,其结构通过波谱分析证实为没食子酰白芍苷,另外还有2个为首次从该植物中分离得到。第二部分报道了芍药苷的微生物转化生产芍药苷代谢素-I的研究,从15株厌氧菌中筛选出10株有转化活性的菌株,其中短乳杆菌Lactobacillus brevis AS1.12的转化活性最好,对其转化条件进行了初步的筛选,确定了相对合理的转化工艺。 在第2章报道了天山雪莲(Saussurea involucrate Kar.et Kir.)全草乙醇提取物化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化和MS、NMR等波谱解析,共分离鉴定了28个化合物,结构类型分属于黄酮、倍半萜和木脂素等,其中2个新倍半萜化合物的结构分别表征为6α-羟基云木香酸6-β-D-吡喃葡萄糖苷和11βH-11,13-二氢去氢云木香内酯8α-O-(6′-乙酰)-β-D-吡喃葡萄糖苷。 第3章报道了两面针(Zanthoxylum nitidum (Roxb.)DC.)干燥根的乙醇提取物化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化和MS、NMR等波谱解析以及X-射线单晶衍射,共分离鉴定了16个生物碱,结构类型分属于苯并啡啶类、喹啉类和阿朴啡类等,其中2个新苯并啡啶类生物碱的结构分别表征为二聚双氢两面针碱和丙酮基双氢崖定椒碱。 第4章报道了通关藤(Marsdenia tenacissima (Roxb.) Wight et Arn.)水提取物化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化和MS、NMR等波谱解析以及X-射线单晶衍射,共分离鉴定了14个化合物,结构类型均属于C21多羟基甾醇,其中4个新化合物tenacigenoside A, tenacigenoside B, tenacigenoside C和tenacigenoside D的结构分别表征为3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-17β-tenacigenin B (62), 3-O-2,6- dideoxy-4-O-methyl-D-lyxo-hexopyranosly-11α-O- methylbutyryl-12β-O-acetyl-tenacigenin B (63), 3-O-6-deoxy-3-O-methyl-β-D- allopyranosyl-(1→4)-β-D-oleandropyranosyl-11α-O-tigloyl-tenacigenin C (64)和3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-11α-O-2- methylbutyryl-tenacigenin C (65)。 第5章概述了花椒属植物的化学成分及药理活性研究进展。 This dissertation consists of 5 chapters. The first chapter elaborate the phytochemical investigation of Paeonia lactiflora Pall., and microbial transformation of paeoniforin. The second, third and four chapters elaborate the phytochemical investigation of Saussurea involucrate Kar.et Kir., Zanthoxylum nitidum (Roxb.) DC. and Marsdenia tenacissima (Roxb.) Wight et Arn., respectively. Chapter 5 is a review on chemical constituents and bioactivities of Zanthoxylum species. The part one of chapter 1 focus on the isolation and identification of chemical constituents from P. lactiflora. Fourteen compounds were isolated from the roots of P. lactiflora by repeat column chromatography over normal and reversed phase silica gel. Among them, one is a new compound and the structure was suggested as galloyl-albiflorin by spectral evidence. In addition, two compounds were firstly reported in this plant. The part 2 is about microbial transformation of paeoniforin. Chapters 2, 3 and 4 were isolations and identifications of chemical constituents from S. involucrate, Z. nitidum and M. tenacissima, respectively. From the aerial parts of S. involucrate, 28 compounds including 7 flavonoids and 13 sesquiterpenoids were isolated and identified. Among them, 2 new compounds were characterized as 6α-hydroxycostic acid 6-β-D-glucoside and 11βH-11,13-dihydrodehydro- costuslactone 8α-O-(6'-acetyl)-β-D-glucoside, respectively, by means of spectroscopic analysis. Otherwise, 11 ones were firstly reported from this plant. The third chapter is about the phytochemical investigation of Z. nitidum. Sixteen compounds were isolated and identified. Among them, 2 new benzophenanthridine alkaloids were characterized as 8-acetonyldihydrofagaridine and 1,3-bis(8-dihydronitidinyl)-acetone by spectroscopic analysis. The fourth chapter is about the phytochemical investigation of M. tenacissima. Fourteen compounds were isolated and identified. Among them, 4 new compounds, tenacigenosides A~D, were characterized as 3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-17β- tenacigenin B, 3-O-2,6-dideoxy-4-O-methyl-D-lyxo-hexopyranosly-11α-O-methyl butyryl-12β-O-acetyl-tenacigenin B, 3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl- (1→4)-β-D-oleandropyranosyl-11α-O-tigloyl-tenacigenin C, and 3-O-6-deoxy-3-O- methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-11α-O-2-methylbutyryl- tenacigenin C. Chapter 5 is a review on recent progress in bioactive constituents from plants of Zanthoxylum species.

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The "teaching signal" that modulates reinforcement learning at cortico-striatal synapses may be a sequence composed of an adaptively scaled DA burst, a brief ACh burst, and a scaled ACh pause. Such an interpretation is consistent with recent data on cholinergic interneurons of the striatum are tonically active neurons (TANs) that respond with characteristic pauses to novel events and to appetitive and aversive conditioned stimuli. Fluctuations in acetylcholine release by TANs modulate performance- and learning- related dynamics in the striatum. Whereas tonic activity emerges from intrinsic properties of these neurons, glutamatergic inputs from thalamic centromedian-parafascicular nuclei, and dopaminergic inputs from midbrain are required for the generation of pause responses. No prior computational models encompass both intrinsic and synaptically-gated dynamics. We present a mathematical model that robustly accounts for behavior-related electrophysiological properties of TANs in terms of their intrinsic physiological properties and known afferents. In the model balanced intrinsic hyperpolarizing and depolarizing currents engender tonic firing, and glutamatergic inputs from thalamus (and cortex) both directly excite and indirectly inhibit TANs. If the latter inhibition, probably mediated by GABAergic NOS interneurons, exceeds a threshold, its effect is amplified by a KIR current to generate a prolongued pause. In the model, the intrinsic mechanisms and external inputs are both modulated by learning-dependent dopamine (DA) signals and our simulations revealed that many learning-dependent behaviors of TANs are explicable without recourse to learning-dependent changes in synapses onto TANs.

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The giant cholinergic interneurons of the striatum are tonically active neurons (TANs) that respond with characteristic pauses to novel events and to appetitive and aversive conditioned stimuli. Fluctuations in acetylcholine release by TANs modulate performance- and learning-related dynamics in the striatum. Whereas tonic activity emerges from intrinsic properties of these neurons, glutamatergic inputs from thalamic centromedian-parafascicular nuclei, and dopaminergic inputs from midbrain, are required for the generation of pause responses. No prior computational models encompass both intrinsic and synaptically-gated dynamics. We present a mathematical model that robustly accounts for behavior-related electrophysiological properties of TANs in terms of their intrinsic physiological properties and known afferents. In the model, balanced intrinsic hyperpolarizing and depolarizing currents engender tonic firing, and glutamatergic inputs from thalamus (and cortex) both directly excite and indirectly inhibit TANs. If the latter inhibition, presumably mediated by GABAergic interneurons, exceeds a threshold, its effect is amplified by a KIR current to generate a prolonged pause. In the model, the intrinsic mechanisms and external inputs are both modulated by learning-dependent dopamine (DA) signals and our simulations revealed that many learning-dependent behaviors of TANs are explicable without recourse to learning-dependent changes in synapses onto TANs. The "teaching signal" that modulates reinforcement learning at cortico-striatal synapses may be a sequence composed of an adaptively scaled DA burst, a brief ACh burst, and a scaled ACh pause. Such an interpretation is consistent with recent data on cholinergic control of LTD of cortical synapses onto striatal spiny projection neurons.

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Identification of immune modifiers of inherited cancer syndromes may provide a rationale for preventive therapy. Cowden disease (CD) is a genetically heterogeneous inherited cancer syndrome that arises predominantly from germline phosphatase and tensin homologue deleted on chromosome 10 (PTEN) mutation and increased phosphoinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR) signalling. However, many patients with classic CD diagnostic features are mutation-negative for PTEN (PTEN M-Neg). Interferon (IFN)-gamma can modulate the PI3K/mTOR pathway, but its association with PTEN M-Neg CD remains unclear. This study assessed IFN-gamma secretion by multi-colour flow cytometry in a CD kindred that was mutation-negative for PTEN and other known susceptibility genes. Because IFN-gamma responses may be regulated by killer cell immunoglobulin-like receptors (KIR) and respective human leucocyte antigen (HLA) ligands, KIR/HLA genotypes were also assessed. Activating treatments induced greater IFN-gamma secretion in PTEN M-Neg CD peripheral blood lymphocytes versus healthy controls. Increased frequency of activating KIR genes, potentially activating KIR/HLA compound genotypes and reduced frequency of inhibitory genotypes, were found in the PTEN M-Neg CD kindred. Differences of IFN-gamma secretion were observed among PTEN M-Neg CD patients with distinct KIR/HLA compound genotypes. Taken together, these findings show enhanced lymphocyte secretion of IFN-gamma that may influence the PI3K/mTOR CD causal molecular pathway in a PTEN mutation-negative CD kindred.

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Inward rectifier potassium channels of the Kir2 subfamily are important determinants of the electrical activity of brain and muscle cells. Genetic mutations in Kir2.1 associate with Andersen-Tawil syndrome (ATS), a familial disorder leading to stress-triggered periodic paralysis and ventricular arrhythmia. To identify the molecular mechanisms of this stress trigger, we analyze Kir channel function and localization electrophysiologically and by time-resolved confocal microscopy. Furthermore, we employ a mathematical model of muscular membrane potential. We identify a novel corticoid signaling pathway that, when activated by glucocorticoids, leads to enrichment of Kir2 channels in the plasma membranes of mammalian cell lines and isolated cardiac and skeletal muscle cells. We further demonstrate that activation of this pathway can either partly restore (40% of cases) or further impair (20% of cases) the function of mutant ATS channels, depending on the particular Kir2.1 mutation. This means that glucocorticoid treatment might either alleviate or deteriorate symptoms of ATS depending on the patient's individual Kir2.1 genotype. Thus, our findings provide a possible explanation for the contradictory effects of glucocorticoid treatment on symptoms in patients with ATS and may open new pathways for the design of personalized medicines in ATS therapy. © FASEB.

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The Cappadocian variety of Ulaghátsh is unique among the Greek-speaking world in having lost the inherited preposition ‘se’. The innovation is found with both locative and allative uses and has af-ected both syntactic contexts in which ‘se’ was originally found, that is, as a simple preposition (1) and as the left-occurring member of circumpositions of the type ‘se’ + NP + spatial adverb (2). (1) a. tránse ci [to meidán] en ávʝa see.PST.3SG COMP ART.DEF.SG.ACC yard.SG.ACC COP.3 game.PL.NOM ‘he saw that in the yard is some game’ (Dawkins 1916: 348) b. ta erʝó da qardáʃa évɣan [to qonáq] ART.DEF.PL.NOM two ART.DEF.PL.NOM friend.PL.NOM ascend.PST.3PL ART.DEF.SG.ACC house.SG.ACC ‘the two friends went up to the house’ (Dawkins 1916: 354) (2) émi [ta qonáca mésa], kiríʃde [to ʝasdɯ́q píso] enter.PST.3SG ART.DEF.PL.NOM house.PL.ACC inside hide.PST.3SG. ART.DEF.SG.ACC cushion.SG.ACC behind ‘he went into the houses and hid behind the cushions’ (Dawkins 1916: 348) In this paper, we set out to provide (a) a diachronic account of the loss of ‘se’ in Asia Minor Greek, and (b) a synchronic analysis of its ramifications for the encoding of the semantic and grammatical functions it had prior to its loss. The diachronic development of ‘se’ is traced by comparing the Ulaghátsh data with those obtained from Cappadocian varieties that have neither lost it nor do they show signs of losing it and, crucially, also from varieties in which ‘se’ is in the process of being lost. The comparative analysis shows that the loss first became manifest in circumpositions in which ‘se’ was preposed to the complement to which in turn a wide range of adverbs expressing topological relations were postposed (émi sa qonáca mésa > émi ta qonáca mésa). This finding is accounted for in terms of Sinha and Kuteva’s (1995) distributed spatial semantics framework, which accepts that the elements involved in the constructions under investigation—the verb (émi), ‘se’ and the spatial adverb (mésa)—all contribute to the expression of the spatial relational meaning but with differences in weighting. Of the three, ‘eis’ made the most minimal contribution, the bulk of it being distributed over the verb and the adverb. This allowed for it to be optionally dropped from circumpositions, a stage attested in Phlo-tá Cappadocian and Silliot, and to be later completely abandoned, originally in allative and subsequently in locative contexts (earlier: évɣan so qonáq > évɣan to qonáq; later: so meidán en ávʝa > to meidán en ávʝa). The earlier loss in allative contexts is also dealt with in distributed semantics terms as verbs of motion such as έβγαν are semantically more loaded than vacuous verbs like the copula and therefore the preposition could be left out in the former context more easily than in the latter. The analysis also addresses the possibility that the loss of ‘se’ may ultimately originate in substandard forms of Medieval Greek, which according to Tachibana (1994) displayed SPATIAL ADVERB + NP constructions. Applying the semantic map model (Croft 2003, Haspelmath 2003), the synchronic analysis of the varieties that retain ‘se’ reveals that—like many other allative markers crosslinguistically—it displays a pattern of multifunctionality in expressing nine different functions (among others allative, locative, recipient, addressee, experiencer), which can be mapped against four domains, viz. the spatiotemporal, the social, the mental and the logicotextual (cf. Rice & Kabata 2007). In Ulaghátsh Cappadocian, none of these functions is overtly marked as such. In cases like (1), the intended spatial relational meaning is arrived at through the combination of the syntax and the inherent semantics of the verb and the zero-marked NP as well as from the context. In environments of the type exemplified by (2), the adverb contributes further to the correct interpretation. The analysis additionally shows that, despite the loss of ‘se’, Ulaghátsh patterns with all other Cappadocian varieties in one important aspect: Goal and Location are expressed similarly (by zero in Ulaghátsh, by ‘se’ in the other varieties) whereas Source is being kept distinct (expressed by ‘apó’ in all varieties). Goal-Location polysemy is very common across the world’s languages and, most crucially, prevails over other possible polysemies in the tripartite distinction Source—Location—Goal (Lestrade 2010, Nikitina 2009). Taking into account this empirical observation, our findings suggest that the reor-anisation of spatial systems can have a local effect—in our case the loss of a member of the prepositional paradigm—but will keep the original global picture intact, thus conforming to crosslinguistically robust tendencies.  References Croft, W. 2001. Radical Construction Grammar: Syntactic Theory in Typological Perspective. Oxford: Oxford University Press. Dawkins, R. M. 1916. Modern Greek in Asia Minor: A Study of the Dialects of Sílli, Cappadocia and Phárasa with Grammar, Texts, Translations and Glossary. Cambridge: Cambridge University Press. Haspelmath, M. 2003. The geometry of grammatical meaning: semantic maps and cross-linguistic comparison. In M. Tomasello (Ed.), The New Psychology of Language, Volume 2. New York: Erlbaum, 211–243. Lestrade, S. 2010. The Space of Case. Doctoral dissertation. Radboud University Nijmegen. Nikitina, T. 2009. Subcategorization pattern and lexical meaning of motion verbs: a study of the source/goal ambiguity. Linguistics 47, 1113–1141. Rice, S. & K. Kabata. 2007. Cross-linguistic grammaticalization patterns of the allative. Linguistic Typology 11, 451–514. Sinha, C. & T. Kuteva. 1995. Distributed spatial semantics. Nordic Journal of Linguistics 18:2, 167–199. Tachibana, T. 1994. Syntactic structure of spatial expressions in the “Late Byzantine Prose Alexander Romance”. Propylaia 6, 35–51.

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La leucémie lymphoblastique aiguë des cellules Pré-B (B-ALL) reste le type de cancer le plus souvent diagnostiqué chez les enfants. Des études ont montré que des déterminants génétiques jouent un rôle important dans la susceptibilité/résistance au développement de ce cancer. À cet égard, les gènes Killer-cell Immunoglobulin-like Receptor (KIR) sont d'une importance particulière. Ces gènes sont fortement polymorphiques et codent pour des récepteurs qui contrôlent l’activité fonctionnelle des cellules Natural Killer (NK). Notre hypothèse est que les gènes activateurs des KIR s’associent avec la résistance innée pour développer la B-ALL. Afin d'évaluer cette hypothèse, nous avons entrepris une étude de cas-contrôles chez des enfants canadiens-français dans laquelle nous avons utilisé l'ADN génomique de 100 patients atteints de B-ALL ainsi que l’ADN de 245 individus sains. La présence ou l'absence de chaque gène KIR a été détectée par PCR en utilisant des amorces de séquences spécifiques. Nous avons trouvé que la présence des gènes KIR activateurs est significativement diminuée chez les enfants leucémiques par rapport aux témoins. En outre, le nombre de ces gènes a aussi montré une association significative linéaire avec la résistance au développement d’une B-ALL. Cela suggère des effets additifs de ces gènes permettant de conférer une protection contre ce cancer. Ces résultats pourraient être utiles afin de déceler de façon précoce les enfants ayant un risque de développer cette leucémie. Enfin, des stratégies thérapeutiques basées sur les récepteurs KIR pourraient être envisagées et s'avérer utiles concernant le traitement de ce cancer chez les enfants.

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Previous BAC clone analysis of the Platyrrhini owl monkey KIRs have shown an unusual genetic structure in some loci. Therefore, cDNAs encoding KIR molecules from eleven Aotus vociferans monkeys were characterized here; tenputative KIR loci were found, some of which encoded atypical proteins such as KIR4DL and transcripts predicted to encode a D0+D1 configuration (AOTVOKIR2DL1*01v1) which appear to be unique in the Aotus genus. Furthermore, alternative splicing was found as a likely mechanism for producing activator receptors in A. vociferans species. KIR proteins from New World monkeys may be split into three new lineages according to domain by domain phylogenetic analysis. Although the A. vociferans KIR family displayed a high divergence among paralogous genes, individual loci were limited in their genetic polymorphism. Selection analysis showed that both constrained and rapid evolution may operate within the AvKIR family. The frequent alternative splicing (as a likely mechanism generating activator receptors), the presence of KIR4DL and KIR2DL1 (D0+D1) molecules and other data reported here suggest that the KIR family in Aotus has had a rapid evolution, independent from its Catarrhini counterparts.from its Catarrhini counterparts.

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Se realizó un estudio cualitativo exploratorio con estudiantes de carreras de Ciencias de la Salud con el objetivo de comprender las representaciones sociales que tienen acerca de la Medicina Complementaria y Alternativa (MCA) para el cáncer. Se desarrollaron grupos focales y la información obtenida fue analizada a través del Análisis Temático e interpretada con base en la Teoría de las Representaciones Sociales. Se encontraron diversas representaciones sociales asociadas con la definición, los objetivos, los tratamientos, la eficacia, las fuentes de información y el origen de la MCA. En conclusión se evidenció una alta tendencia a la aceptación y a la manifestación de una actitud positiva, aunque ambivalente frente a la MCA, además de un desconocimiento por la diferenciación conceptual entre este tipo de Medicina y la Medicina Popular. La cultura y las creencias sociales predominan en las representaciones sociales que tienen los estudiantes de la MCA para el cáncer, pese a su formación académica.

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El texto presenta una teoría crítica de la enseñanza en la educación física. El libro se estructura en dos grandes partes: en la primera parte, se realiza una visión panorámica, desde una perspectiva crítica, del campo del currículum en relación a la educación física. Y en la segunda parte, se somete a discusión algunos de los tópicos dominantes de los estudios del currículum en la educación física.

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Ayuda a desarrollar en los niños las habilidades para la lectura y la ortografía, a conocer los fonemas vocales y a distinguir entre fonema y grafema. Todo esto con el apoyo fónico de las historias, de esta misma serie, contadas para las etapas escolares de la cuatro a la seis y de la siete a la nueve. Cumple con los requisitos del plan de estudios del Reino Unido, y, en particular, con la Estrategia nacional de alfabetización (National Literacy Strategy).

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Comprende una serie de materiales que satisfacen las demandas de aprendizaje de lectura y escritura de los niños dentro de un plan de estudios diseñados además conforme a unos principios: textos estructurados, de agradable y enriquecedora lectura. Para ello, tiene textos de ficción y no ficción, para edades de 4 a 7 años y, que pueden ser utilizados para la lectura compartida, para trabajo en grupo y para lectura independiente.

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Se propone a los niños del nivel educativo de primaria, la realización de actividades prácticas para que exploren e investiguen las propiedades, la composición y los cambios que sufren los distintos tipos de materiales que se les ofrecen (metal, papel, plástico,etc). También se les anima a que, siguiendo los pasos de una investigación científica, realicen experimentos con ellos. Se acompaña el libro de hojas fotocopiables y actividades de evaluación para el profesor.

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El modelo del idioma inglés que se debe utilizar en las aulas ha sido durante mucho tiempo un tema de debate. Este texto describe las variedades mundiales de lengua inglesa, y discute las ventajas y desventajas de seleccionar una variedad determinada como segunda lengua desde el punto de vista de profesores y alumnos. Examina y evalúa nuevos conceptos tales como 'estándar', 'variedad', 'nativo' y 'hablante no nativo', para validar el papel desempeñado por los profesores de inglés multilingüe y multicultural, con el argumento de que las necesidades del contexto y el alumno deben determinar la variedad que se les enseñe. Viene acompañado de un CD de audio.

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Texto de biología para preparar el Certificado de Educación Secundaria del Caribe (CSEC). Ofrece cinco secciones para el examen de aptitud general, cada una dividida en unidades con los objetivos de aprendizaje, actividades prácticas, sucesos importantes y estudios de casos para estimular el interés y ayudar en el aprendizaje. Incluye trabajos prácticos y experimentos, referencias al medio ambiente local y una sección con preguntas de revisión de exámenes para ayudar a los estudiantes a integrar el aprendizaje, revisar los conceptos y aprender a preparar la prueba según la School-Based Assesment (SBA).