787 resultados para Daily creativity and peripheral youths
Resumo:
A opressão e a resistência são um fio condutor dos Salmos de peregrinação, o grupo que vai do Salmo 120 até o 134. O distintivo situa-se nas formas variadas com que estas categorias são apresentadas. Este conjunto de salmos impressiona pela maneira simples e direita de dizer as coisas, sem deixar de ser profunda. A partir da análise, observamos que a opressão e a resistência surgem em variadas formas, deixando transparecer que não se trata de falar delas em sentido geral, pois envolvem diferentes formas e facetas que se entrecruzam, sendo manifestas por meio de relações de gênero, classe e raça/etnia. O objetivo desta tese é provar que a partir dos movimentos dos corpos, suas falas e suas memórias é possível apontar para práticas de relacionamentos sociais, econômicos, políticos ou religiosos, marcadas por relações de gênero, raça/etnia, classe, que não se vinculam aos interesses de sistemas institucionais. Mas surgem da interação entre experiências de opressão e resistência e se colocam como alternativas de vida. Cada salmo traz marcas de um contexto particular que se junta às particularidades do outro até revelar um único contexto e nessa dinâmica possibilitar o conjunto. Através das estruturas, formas literárias e dos conteúdos, aponta-se para a centralidade do corpo como sendo fator hermenêutico ativo que, com seu movimento, sua fala, suas memórias, mostra situações de opressão e busca por prazer. O estudo literário e os conteúdos são determinantes, tanto para a estrutura do conjunto, dividida em três grandes partes (Sl 120-122; 123-129 e 130-134), para a tematização do desenvolvimento do conjunto, quanto para a credibilidade da proposta histórica de opressão e resistência apresentada. Constata-se que a vida religiosa aparece integrada à vida social e política da qual constitui um aspecto se bem que existe mais de uma experiência religiosa, inter-relacionada. Estas experiências revelam que as visitas ao templo de Jerusalém não só eram para cumprir com os costumes religiosos, daquela época, mas principalmente, pelo interesse que peregrinos e peregrinas tinham no cotidiano de suas vidas, seus trabalhos, suas necessidades. Elas e eles souberam fazer a articulação entre a festa e a práxis. Assim, o conjunto de salmos torna-se ponte para o diálogo que revela outras vozes e outras maneiras de identificar opressão e resistência. Não para fugir ou acomodar-se, senão reconhecendo a opressão, superando-a na criatividade e na esperança. O estudo desenvolve-se em quatro capítulos. No primeiro, enfatiza-se que os textos estão entre teologia e literatura, especificamente em serem textos poéticos. A partir daí levanta-se o estado atual do estudo sobre este conjunto de salmos e aponta-se ao contexto histórico ao qual estão relacionados estes salmos. No segundo, realiza-se a análise das estruturas poéticas, até entenderque o conjunto de salmo está relacionado como um todo. No terceiro e quarto, pelos resultados do segundo, destacam-se os principais temas que de forma indiciária levam-nos à demonstração da hipótese.
Resumo:
SOCS-1, a member of the suppressor of cytokine signaling (SOCS) family, was identified in a genetic screen for inhibitors of interleukin 6 signal transduction. SOCS-1 transcription is induced by cytokines, and the protein binds and inhibits Janus kinases and reduces cytokine-stimulated tyrosine phosphorylation of signal transducers and activators of transcription 3 and the gp130 component of the interleukin 6 receptor. Thus, SOCS-1 forms part of a feedback loop that modulates signal transduction from cytokine receptors. To examine the role of SOCS-1 in vivo, we have used gene targeting to generate mice lacking this protein. SOCS-1−/− mice exhibited stunted growth and died before weaning with fatty degeneration of the liver and monocytic infiltration of several organs. In addition, the thymus of SOCS-1−/− mice was reduced markedly in size, and there was a progressive loss of maturing B lymphocytes in the bone marrow, spleen, and peripheral blood. Thus, SOCS-1 is required for in vivo regulation of multiple cell types and is indispensable for normal postnatal growth and survival.
Resumo:
Two cannabinoid receptors have been identified: CB1, present in the central nervous system (CNS) and to a lesser extent in other tissues, and CB2, present outside the CNS, in peripheral organs. There is evidence for the presence of CB2-like receptors in peripheral nerve terminals. We report now that we have synthesized a CB2-specific agonist, code-named HU-308. This cannabinoid does not bind to CB1 (Ki > 10 μM), but does so efficiently to CB2 (Ki = 22.7 ± 3.9 nM); it inhibits forskolin-stimulated cyclic AMP production in CB2-transfected cells, but does so much less in CB1-transfected cells. HU-308 shows no activity in mice in a tetrad of behavioral tests, which together have been shown to be specific for tetrahydrocannabinol (THC)-type activity in the CNS mediated by CB1. However, HU-308 reduces blood pressure, blocks defecation, and elicits anti-inflammatory and peripheral analgesic activity. The hypotension, the inhibition of defecation, the anti-inflammatory and peripheral analgesic effects produced by HU-308 are blocked (or partially blocked) by the CB2 antagonist SR-144528, but not by the CB1 antagonist SR-141716A. These results demonstrate the feasibility of discovering novel nonpsychotropic cannabinoids that may lead to new therapies for hypertension, inflammation, and pain.
Resumo:
Antigen-induced stimulation of the immune system can generate heterogeneity in CD4+ T cell division rates capable of explaining the temporal patterns seen in the decay of HIV-1 plasma RNA levels during highly active antiretroviral therapy. Posttreatment increases in peripheral CD4+ T cell counts are consistent with a mathematical model in which host cell redistribution between lymph nodes and peripheral blood is a function of viral burden. Model fits to patient data suggest that, although therapy reduces HIV replication below replacement levels, substantial residual replication continues. This residual replication has important consequences for long-term therapy and the evolution of drug resistance and represents a challenge for future treatment strategies.
Resumo:
Potent antiretroviral therapy can reduce plasma HIV RNA levels below the threshold of detection for periods of a year or more. The magnitude of HIV RNA reduction in the lymphoid tissue in patients with suppression of HIV RNA levels in plasma beyond 6 months has not been determined. We evaluated levels of HIV RNA and DNA and characterized resistance mutations in blood and inguinal lymph node biopsies obtained from 10 HIV-infected subjects who received 36–52 weeks of indinavir (IDV)/zidovudine (ZDV)/lamivudine (3TC), IDV, or ZDV/3TC. After 1 year of therapy, viral RNA levels in LN of individuals remained detectable but were log10 = 4 lower than in subjects on the triple drug regimen with interruption of therapy or in those treated with ZDV/3TC alone, who had viral loads in their lymph nodes indistinguishable from those expected for untreated patients. In all cases viral DNA remained detectable in lymph nodes and peripheral blood mononuclear cells (PBMC). When plasma virus suppression was incomplete, lymph node and PBMC cultures were positive and drug resistance developed. These studies indicate that pronounced and sustained suppression of plasma viremia by a potent antiretroviral combination is associated with low HIV RNA levels in the lymph nodes 1 year after treatment. Conversely, the persistence of even modest levels of plasma virus after 1 year of treatment reflects ongoing viral replication, the emergence of drug resistance, and the maintenance of high burdens of virus in the lymph nodes.
Resumo:
Yeast Sec22p participates in both anterograde and retrograde vesicular transport between the endoplasmic reticulum (ER) and the Golgi apparatus by functioning as a v-SNARE (soluble N-ethylmaleimide-sensitive factor [NSF] attachment protein receptor) of transport vesicles. Three mammalian proteins homologous to Sec22p have been identified and are referred to as Sec22a, Sec22b/ERS-24, and Sec22c, respectively. The existence of three homologous proteins in mammalian cells calls for detailed cell biological and functional examinations of each individual protein. The epitope-tagged forms of all three proteins have been shown to be primarily associated with the ER, although functional examination has not been carefully performed for any one of them. In this study, using antibodies specific for Sec22b/ERS-24, it is revealed that endogenous Sec22b/ERS-24 is associated with vesicular structures in both the perinuclear Golgi and peripheral regions. Colabeling experiments for Sec22b/ERS-24 with Golgi mannosidase II, the KDEL receptor, and the envelope glycoprotein G (VSVG) of vesicular stomatitis virus (VSV) en route from the ER to the Golgi under normal, brefeldin A, or nocodazole-treated cells suggest that Sec22b/ERS-24 is enriched in the pre-Golgi intermediate compartment (IC). In a well-established semi-intact cell system that reconstitutes transport from the ER to the Golgi, transport of VSVG is inhibited by antibodies against Sec22b/ERS-24. EGTA is known to inhibit ER–Golgi transport at a stage after vesicle/transport intermediate docking but before the actual fusion event. Antibodies against Sec22b/ERS-24 inhibit ER–Golgi transport only when they are added before the EGTA-sensitive stage. Transport of VSVG accumulated in pre-Golgi IC by incubation at 15°C is also inhibited by Sec22b/ERS-24 antibodies. Morphologically, VSVG is transported from the ER to the Golgi apparatus via vesicular intermediates that scatter in the peripheral as well as the Golgi regions. In the presence of antibodies against Sec22b/ERS-24, VSVG is seen to accumulate in these intermediates, suggesting that Sec22b/ERS-24 functions at the level of the IC in ER–Golgi transport.
Resumo:
cDNA clones encoding a novel protein (VAMP5) homologous to synaptobrevins/VAMPs are detected during database searches. The predicted 102–amino acid VAMP5 harbors a 23-residue hydrophobic region near the carboxyl terminus and exhibits an overall amino acid identity of 33% with synaptobrevin/VAMP1 and 2 and cellubrevin. Northern blot analysis reveals that the mRNA for VAMP5 is preferentially expressed in the skeletal muscle and heart, whereas significantly lower levels are detected in several other tissues but not in the brain. During in vitro differentiation (myogenesis) of C2C12 myoblasts into myotubes, the mRNA level for VAMP5 is increased ∼8- to 10-fold. Immunoblot analysis using antibodies specific for VAMP5 shows that the protein levels are also elevated ∼6-fold during in vitro myogenesis of C2C12 cells. Indirect immunofluorescence microscopy and immunoelectron microscopy reveal that VAMP5 is associated with the plasma membrane as well as intracellular perinuclear and peripheral vesicular structures of myotubes. Epitope-tagged versions of VAMP5 are similarly targeted to the plasma membrane.
Resumo:
Rho family proteins have been implicated in regulating various cellular processes, including actin cytoskeleton organization, endocytosis, cell cycle, and gene expression. In this study, we analyzed the function of a novel Dictyostelium discoideum Rho family protein (RacC). A cell line was generated that conditionally overexpressed wild-type RacC three- to fourfold relative to endogenous RacC. Light and scanning electron microscopy indicated that the morphology of the RacC-overexpressing cells [RacC WT(+) cells] was significantly altered compared with control cells. In contrast to the cortical F-actin distribution normally observed, RacC WT(+) cells displayed unusual dorsal and peripheral F-actin–rich surface blebs (petalopodia, for flower-like). Furthermore, phagocytosis in the RacC WT(+) cells was induced threefold relative to control Ax2 cells, whereas fluid-phase pinocytosis was reduced threefold, primarily as the result of an inhibition of macropinocytosis. Efflux of fluid-phase markers was also reduced in the RacC WT(+) cells, suggesting that RacC may regulate postinternalization steps along the endolysosomal pathway. Treatment of cells with Wortmannin and LY294002 (phosphatidylinositol 3-kinase inhibitors) prevented the RacC-induced morphological changes but did not affect phagocytosis, suggesting that petalopodia are probably not required for RacC-induced phagocytosis. In contrast, inactivating diacylglycerol-binding motif–containing proteins by treating cells with the drug calphostin C completely inhibited phagocytosis in control and RacC WT(+) cells. These results suggest that RacC plays a role in actin cytoskeleton organization and phagocytosis in Dictyostelium.
Resumo:
HMG I(Y) proteins bind to double-stranded A+T oligonucleotides longer than three base pairs. Such motifs form part of numerous NF-AT-binding sites of lymphokine promoters, including the interleukin 4 (IL-4) promoter. NF-AT factors share short homologous peptide sequences in their DNA-binding domain with NF-κB factors and bind to certain NF-κB sites. It has been shown that HMG I(Y) proteins enhance NF-κB binding to the interferon β promoter and virus-mediated interferon β promoter induction. We show that HMG I(Y) proteins exert an opposite effect on the DNA binding of NF-AT factors and the induction of the IL-4 promoter in T lymphocytes. Introduction of mutations into a high-affinity HMG I(Y)-binding site of the IL-4 promoter, which decreased HMG I(Y)-binding to a NF-AT-binding sequence, the Pu-bB (or P) site, distinctly increased the induction of the IL-4 promoter in Jurkat T leukemia cells. High concentrations of HMG I(Y) proteins are able to displace NF-ATp from its binding to the Pu-bB site. High HMG I(Y) concentrations are typical for Jurkat cells and peripheral blood T lymphocytes, whereas El4 T lymphoma cells and certain T helper type 2 cell clones contain relatively low HMG I(Y) concentrations. Our results indicate that HMG I(Y) proteins do not cooperate, but instead compete with NF-AT factors for the binding to DNA even though NF-AT factors share some DNA-binding properties with NF-kB factors. This competition between HMG I(Y) and NF-AT proteins for DNA binding might be due to common contacts with minor groove nucleotides of DNA and may be one mechanism contributing to the selective IL-4 expression in certain T lymphocyte populations, such as T helper type 2 cells.
Resumo:
Sandhoff disease is a neurodegenerative disorder resulting from the autosomal recessive inheritance of mutations in the HEXB gene, which encodes the β-subunit of β-hexosaminidase. GM2 ganglioside fails to be degraded and accumulates within lysosomes in cells of the periphery and the central nervous system (CNS). There are currently no therapies for the glycosphingolipid lysosomal storage diseases that involve CNS pathology, including the GM2 gangliosidoses. One strategy for treating this and related diseases is substrate deprivation. This would utilize an inhibitor of glycosphingolipid biosynthesis to balance synthesis with the impaired rate of catabolism, thus preventing storage. One such inhibitor is N-butyldeoxynojirimycin, which currently is in clinical trials for the potential treatment of type 1 Gaucher disease, a related disease that involves glycosphingolipid storage in peripheral tissues, but not in the CNS. In this study, we have evaluated whether this drug also could be applied to the treatment of diseases with CNS storage and pathology. We therefore have treated a mouse model of Sandhoff disease with the inhibitor N-butyldeoxynojirimycin. The treated mice have delayed symptom onset, reduced storage in the brain and peripheral tissues, and increased life expectancy. Substrate deprivation therefore offers a potentially general therapy for this family of lysosomal storage diseases, including those with CNS disease.
Resumo:
Nuclear LIM domains interact with a family of coregulators referred to as Clim/Ldb/Nli. Although one family member, Clim-2/Ldb-1/Nli, is highly expressed in epidermal keratinocytes, no nuclear LIM domain factor is known to be expressed in epidermis. Therefore, we used the conserved LIM-interaction domain of Clim coregulators to screen for LIM domain factors in adult and embryonic mouse skin expression libraries and isolated a factor that is highly homologous to the previously described LIM-only proteins LMO-1, -2, and -3. This factor, referred to as LMO-4, is expressed in overlapping manner with Clim-2 in epidermis and in several other regions, including epithelial cells of the gastrointestinal, respiratory and genitourinary tracts, developing cartilage, pituitary gland, and discrete regions of the central and peripheral nervous system. Like LMO-2, LMO-4 interacts strongly with Clim factors via its LIM domain. Because LMO/Clim complexes are thought to regulate gene expression by associating with DNA-binding proteins, we used LMO-4 as a bait to screen for such DNA-binding proteins in epidermis and isolated the mouse homologue of Drosophila Deformed epidermal autoregulatory factor 1 (DEAF-1), a DNA-binding protein that interacts with regulatory sequences first described in the Deformed epidermal autoregulatory element. The interaction between LMO-4 and mouse DEAF-1 maps to a proline-rich C-terminal domain of mouse DEAF-1, distinct from the helix–loop–helix and GATA domains previously shown to interact with LMOs, thus defining an additional LIM-interacting domain.
Resumo:
Embolism and refilling of vessels was monitored directly by cryomicroscopy of field-grown corn (Zea mays L.) roots. To test the reliability of an earlier study showing embolism refilling in roots at negative leaf water potentials, embolisms were counted, and root water potentials (Ψroot) and osmotic potentials of exuded xylem sap from the same roots were measured by isopiestic psychrometry. All vessels were full at dawn (Ψroot −0.1 MPa). Embolisms were first seen in late metaxylem vessels at 8 am. Embolized late metaxylem vessels peaked at 50% at 10 am (Ψroot −0.1 MPa), fell to 44% by 12 pm (Ψroot −0.23 MPa), then dropped steadily to zero by early evening (Ψroot −0.28 MPa). Transpiration was highest (8.5 μg cm−2 s−1) between 12 and 2 pm when the percentage of vessels embolized was falling. Embolized vessels were refilled by liquid moving through their lateral walls. Xylem sap was very low in solutes. The mechanism of vessel refilling, when Ψroot is negative, requires further investigation. Daily embolism and refilling in roots of well-watered plants is a normal occurrence and may be a component of an important hydraulic signaling mechanism between roots and shoots.
Resumo:
Perilipin coats the lipid droplets of adipocytes and is thought to have a role in regulating triacylglycerol hydrolysis. To study the role of perilipin in vivo, we have created a perilipin knockout mouse. Perilipin null (peri−/−) and wild-type (peri+/+) mice consume equal amounts of food, but the adipose tissue mass in the null animals is reduced to ≈30% of that in wild-type animals. Isolated adipocytes of perilipin null mice exhibit elevated basal lipolysis because of the loss of the protective function of perilipin. They also exhibit dramatically attenuated stimulated lipolytic activity, indicating that perilipin is required for maximal lipolytic activity. Plasma leptin concentrations in null animals were greater than expected for the reduced adipose mass. The peri−/− animals have a greater lean body mass and increased metabolic rate but they also show an increased tendency to develop glucose intolerance and peripheral insulin resistance. When fed a high-fat diet, the perilipin null animals are resistant to diet-induced obesity but not to glucose intolerance. The data reveal a major role for perilipin in adipose lipid metabolism and suggest perilipin as a potential target for attacking problems associated with obesity.
Resumo:
Melanin-concentrating hormone (MCH), a neuropeptide expressed in central and peripheral nervous systems, plays an important role in the control of feeding behaviors and energy metabolism. An orphan G protein-coupled receptor (SLC-1/GPR24) has recently been identified as a receptor for MCH (MCHR1). We report here the identification and characterization of a G protein-coupled receptor as the MCH receptor subtype 2 (MCHR2). MCHR2 has higher protein sequence homology to MCHR1 than any other G protein-coupled receptor. The expression of MCHR2 has been detected in many regions of the brain. In contrast to MCHR1, which is intronless in the coding region and is located at the chromosomal locus 22q13.3, the MCHR2 gene has multiple exons and is mapped to locus 6q21. MCHR2 is specifically activated by nanomolar concentrations of MCH, binds to MCH with high affinity, and signals through Gq protein. This discovery is important for a full understanding of MCH biology and the development of potential therapeutics for diseases involving MCH, including obesity.
Resumo:
A unique gene, RBP-MS, spanning over 230 kb in the human chromosome 8p11-12 near the Werner syndrome gene locus is described. The single-copy RBP-MS gene is alternatively spliced, resulting in a family of at least 12 transcripts (average length of 1.5 kb). Nine different types of cDNAs that encode an RNa-binding motif at the N terminus and helix-rich sequences at the C terminus have been identified thus far. Among the 16 exons identified, four 5'-proximal exons contained sequences homologous to the RNA-binding domain of Drosophila couch potato gene. Northern blot analysis showed that the RBP-MS gene was expressed strongly in the heart, prostate, intestine, and ovary, and poorly in the skeletal muscle, spleen, thymus, brain, and peripheral leukocytes. The possible role of this gene in RNA metabolism is discussed.