68 research outputs found
SPONTANEOUS-RECOVERY OF RATS FROM EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS IS DEPENDENT ON REGULATION OF THE IMMUNE-SYSTEM BY ENDOGENOUS ADRENAL CORTICOSTEROIDS
Experimental allergic encephalomyelitis (EAE) ' is a paralytic disease that can be induced in a number of animal species by evoking immune responses to antigens in central nervous system (CNS) myelin, and has been studied as a model for multiple sclerosis in man (1). In Lewis rats EAE can be induced either by immunization with guinea pig myelin basic protein (MBP) in CFA (active EAE) or by the intravenous injection into naive syngeneic recipients of spleen cells from animals with active EAE, after in vitro culture of the splenocytes with MBP (passive EAE). The ascending paralysis characteristic of EAE is caused by the action of CD4+ T lymphocytes that produce focal edema in the CNS by increasing vascular permeability (2-4). In both active and passive EAE, animals develop a transient paralysis, and recover completely within 4-5 d of its onset (5). The mechanisms responsible for this spontaneous recovery, which may be similar to the acute remissions occasionally seen in multiple sclerosis, are still poorly understood. Various mechanisms have been proposed, including: suppressor cells (T lymphocytes [6-9], B lymphocytes [10], and macrophages [11]), anti-T lymphocyte idiotype responses (12), serum suppressor factors (13-16), production ofimmunosuppressive factors by filial cells (17-19), regulation by IFN-'Y (20), and neuroendocrine-mediated immunoregulation (21, 22). None of these mechanisms has been shown directly to be necessary for spontaneous recovery from EAE. It has, however, been demonstrated that CD8+ T lymphocytes are not required (23-25). Here we demonstrate that endogenously produced corticosterone plays an essential role in the spontaneous recovery of rats from EAE. Downloaded from jem.rupress.org on February 21, 201
Virtual endocranial and inner ear endocasts of the Paleocene ‘condylarth’ Chriacus: New insight into the neurosensory system and evolution of early placental mammals
Early Adolescent Depressive Symptoms: Prediction from Clique Isolation, Loneliness, and Perceived Social Acceptance
This study examined whether clique isolation predicted an increase in depressive symptoms and whether this association was mediated by loneliness and perceived social acceptance in 310 children followed from age 11–14 years. Clique isolation was identified through social network analysis, whereas depressive symptoms, loneliness, and perceived social acceptance were assessed using self ratings. While accounting for initial levels of depressive symptoms, peer rejection, and friendlessness at age 11 years, a high probability of being isolated from cliques from age 11 to 13 years predicted depressive symptoms at age 14 years. The link between clique isolation and depressive symptoms was mediated by loneliness, but not by perceived social acceptance. No sex differences were found in the associations between clique isolation and depressive symptoms. These results suggest that clique isolation is a social risk factor for the escalation of depressive symptoms in early adolescence. Implications for research and prevention are discussed
Lawson criterion for ignition exceeded in an inertial fusion experiment
For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion
A New Pliocene Capybara (Rodentia, Caviidae) from Northern South America (Guajira, Colombia), and its Implications for the Great American Biotic Interchange
One of the most striking components of the modern assemblage of South American mammals is the semiaquatic capybara (Caviidae, Hydrochoerinae), the biggest rodent in the world. The large hydrochoerines are recorded from the middle Miocene to the present, mainly in high latitudes of South America. Although less known, they are also recorded in low latitudes of South America, and in Central and North America. We report the first record of capybaras from the late Pliocene of Colombia, found in deposits of the Ware Formation, Guajira Peninsula in northeastern Colombia. We analyze the phylogenetic position within Caviidae, the possible environmental changes in the Guajira Peninsula, and the implications of this finding for the understanding of the Great American Biotic Interchange. The morphological and phylogenetic analyses indicate that the hydrochoerine of the Guajira Peninsula is a new species, ?Hydrochoeropsis wayuu, and this genus is most closely related to Phugatherium. According to the latest phylogenetic results, this clade is the sister group of the lineage of the recent capybaras (Neochoerus and Hydrochoerus). ?Hydrochoeropsis wayuu is the northernmost South American Pliocene hydrochoerine record and the nearest to the Panamanian bridge. The presence of this hydrochoerine, together with the fluvio-deltaic environment of the Ware Formation, suggests that during the late Pliocene, the environment that dominated the Guajira Peninsula was more humid and with permanent water bodies, in contrast with its modern desert habitats
Genome organization, phylogenies, expression patterns, and three-dimensional protein models of two acetylcholinesterase genes from the red flour beetle
Citation: Lu, Y., . . . & Zhu, K. (2012). Genome Organization, Phylogenies, Expression Patterns, and Three-Dimensional Protein Models of Two Acetylcholinesterase Genes from the Red Flour Beetle. PLoS ONE, 7(2).
https://doi.org/10.1371/journal.pone.0032288Since the report of a paralogous acetylcholinesterase (AChE, EC3.1.1.7) gene in the greenbug (Schizaphis graminum) in 2002, two different AChE genes (Ace1 and Ace2) have been identified in each of at least 27 insect species. However, the gene
models of Ace1 and Ace2, and their molecular properties have not yet been comprehensively analyzed in any insect species. In this study, we sequenced the full-length cDNAs, computationally predicted the corresponding three-dimensional protein models, and profiled developmental stage and tissue-specific expression patterns of two Ace genes from the red flour beetle (Tribolium castaneum; TcAce1 and TcAce2), a globally distributed major pest of stored grain products and an emerging model organism. TcAce1 and TcAce2 encode 648 and 604 amino acid residues, respectively, and have conserved motifs including a choline-binding site, a catalytic triad, and an acyl pocket. Phylogenetic analysis show that both TcAce
genes are grouped into two insect Ace clusters and TcAce1 is completely diverged from TcAce2, suggesting that these two
genes evolve from their corresponding Ace gene lineages in insect species. In addition, TcAce1 is located on chromosome 5,
whereas TcAce2 is located on chromosome 2. Reverse transcription polymerase chain reaction (PCR) and quantitative realtime
PCR analyses indicate that both genes are virtually transcribed in all the developmental stages and predominately
expressed in the insect brain. Our computational analyses suggest that the TcAce1 protein is a robust acetylcholine (ACh)
hydrolase and has susceptibility to sulfhydryl agents whereas the TcAce2 protein is not a catalytically efficient ACh hydrolase
A Preliminary Study on the Performance of a Flexible Sheetlike Blade Wind Turbine Inspired by the Borneo Camphor Seed
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