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151.
Cohen E Koch L Thu KM Rahamim Y Aluma Y Ilan M Yarden O Carmeli S 《Bioorganic & medicinal chemistry》2011,19(22):6587-6593
Three novel meroterpenoids, insuetolides A-C (1-3) and four drimane sesquiterpenes, the new (E)-6-(4'-hydroxy-2'-butenoyl)-strobilactone A (4) and the known 2α, 9α, 11-trihydroxy-6-oxodrim-7-ene (5), strobilactone A (6) and (E,E)-6-(6',7'-dihydroxy-2',4'-octadienoyl)-strobilactone A (7), were isolated from the EtOAc extract of the culture medium of the marine-derived fungus Aspergillus insuetus (OY-207), which was isolated from the Mediterranean sponge Psammocinia sp. The structures of the compounds were determined by spectroscopic methods. Insuetolides A-C reveal a new carbon skeleton derived from the cyclization of farnesyl and 3, 5-dimethylorsellinic acid. Compounds 1, 6, and 7 exhibited anti-fungal activity towards Neurospora crassa with MIC values of 140, 242, and 162 μM, respectively; and compounds 3, 4, and 7 exhibited mild cytotoxicity towards MOLT-4 human leukemia cells. 相似文献
152.
Zhao J Wu H Khosravi M Cui H Qian X Kelly JA Kaufman KM Langefeld CD Williams AH Comeau ME Ziegler JT Marion MC Adler A Glenn SB Alarcón-Riquelme ME;BIOLUPUS Network;GENLES Network Pons-Estel BA Harley JB Bae SC Bang SY Cho SK Jacob CO Vyse TJ Niewold TB Gaffney PM Moser KL Kimberly RP Edberg JC Brown EE Alarcon GS Petri MA Ramsey-Goldman R Vilá LM Reveille JD James JA Gilkeson GS Kamen DL Freedman BI Anaya JM Merrill JT Criswell LA Scofield RH Stevens AM Guthridge JM Chang DM Song YW Park JA 《PLoS genetics》2011,7(5):e1002079
Systemic lupus erythematosus (SLE), a complex polygenic autoimmune disease, is associated with increased complement activation. Variants of genes encoding complement regulator factor H (CFH) and five CFH-related proteins (CFHR1-CFHR5) within the chromosome 1q32 locus linked to SLE, have been associated with multiple human diseases and may contribute to dysregulated complement activation predisposing to SLE. We assessed 60 SNPs covering the CFH-CFHRs region for association with SLE in 15,864 case-control subjects derived from four ethnic groups. Significant allelic associations with SLE were detected in European Americans (EA) and African Americans (AA), which could be attributed to an intronic CFH SNP (rs6677604, in intron 11, P
meta = 6.6×10−8, OR = 1.18) and an intergenic SNP between CFHR1 and CFHR4 (rs16840639, P
meta = 2.9×10−7, OR = 1.17) rather than to previously identified disease-associated CFH exonic SNPs, including I62V, Y402H, A474A, and D936E. In addition, allelic association of rs6677604 with SLE was subsequently confirmed in Asians (AS). Haplotype analysis revealed that the underlying causal variant, tagged by rs6677604 and rs16840639, was localized to a ∼146 kb block extending from intron 9 of CFH to downstream of CFHR1. Within this block, the deletion of CFHR3 and CFHR1 (CFHR3-1Δ), a likely causal variant measured using multiplex ligation-dependent probe amplification, was tagged by rs6677604 in EA and AS and rs16840639 in AA, respectively. Deduced from genotypic associations of tag SNPs in EA, AA, and AS, homozygous deletion of CFHR3-1Δ (P
meta = 3.2×10−7, OR = 1.47) conferred a higher risk of SLE than heterozygous deletion (P
meta = 3.5×10−4, OR = 1.14). These results suggested that the CFHR3-1Δ deletion within the SLE-associated block, but not the previously described exonic SNPs of CFH, might contribute to the development of SLE in EA, AA, and AS, providing new insights into the role of complement regulators in the pathogenesis of SLE. 相似文献
153.
154.
Dufau S Duñabeitia JA Moret-Tatay C McGonigal A Peeters D Alario FX Balota DA Brysbaert M Carreiras M Ferrand L Ktori M Perea M Rastle K Sasburg O Yap MJ Ziegler JC Grainger J 《PloS one》2011,6(9):e24974
Investigating human cognitive faculties such as language, attention, and memory most often relies on testing small and homogeneous groups of volunteers coming to research facilities where they are asked to participate in behavioral experiments. We show that this limitation and sampling bias can be overcome by using smartphone technology to collect data in cognitive science experiments from thousands of subjects from all over the world. This mass coordinated use of smartphones creates a novel and powerful scientific "instrument" that yields the data necessary to test universal theories of cognition. This increase in power represents a potential revolution in cognitive science. 相似文献
155.
156.
Chayaburakul K Lightner DV Sriurairattana S Nelson KT Withyachumnarnkul B 《Diseases of aquatic organisms》2005,67(3):191-200
Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is widespread in cultured Penaeus monodon and P. vannamei in Thailand. It causes runt-deformity syndrome that is characterized by physical abnormalities and stunted growth in P. vannamei, but causes no apparent disease in P. monodon. In both species, the virus may produce Cowdry Type A inclusions in tissues of ectodermal and mesodermal origin, but these are common in P. vannamei and rare in P. monodon. The virus can be more easily detected in both species by IHHNV-specific PCR primers. By in situ hybridization (ISH) using specific IHHNV probes, fixed phagocytes associated with myocardial cells tended to show strong positive reactions in both shrimp species. Ovarian and neural tissue (neurons in the nerve ganglia and glial cells in the nerve cord) were ISH positive for IHHNV only in P. vannamei. By transmission electron microscopy, necrotic cells were found in the gills of IHHNV-infected P. vannamei, while paracrystalline arrays of virions and apoptotic cells rather than necrotic cells were found in the lymphoid organ of IHHNV-infected P. monodon. Thus, it is possible that apoptosis in P. monodon contributes to the absence of clinical disease from IHHNV. These findings reveal different responses to IHHNV infection by the 2 shrimp species. A curious feature of IHHNV infection in P. monodon was inconsistency in the comparative viral load amongst tissues of different specimens, as detected by both ISH and real-time PCR. This inconsistency in apparent tissue preference and the reasons for different cellular responses between the 2 shrimp species remain unexplained. 相似文献
157.
The unusual perforations in the leaf blades of Monstera obliqua (Araceae) arise through programmed cell death early in leaf development. At each perforation site, a discrete subpopulation of cells undergoes programmed cell death simultaneously, while neighboring protoderm and ground meristem cells are unaffected. Nuclei of cells within the perforation site become terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive, indicating that DNA cleavage is an early event. Gel electrophoresis indicates that DNA cleavage is random and does not result in bands that represent multiples of internucleosomal units. Ultrastructural analysis of cells at the same stage reveals misshapen, densely stained nuclei with condensed chromatin, disrupted vacuoles, and condensed cytoplasm. Cell walls within the perforation site remain intact, although a small disk of dying tissue becomes detached from neighboring healthy tissues as the leaf expands and stretches the minute perforation. Exposed ground meristem cells at the rim of the perforation differentiate as epidermal cells. The cell biology of perforation formation in Monstera resembles that in the aquatic plant Aponogeton madagascariensis (Aponogetonaceae; Gunawardena et al. 2004), but the absence of cell wall degradation and the simultaneous execution of programmed cell death throughout the perforation site reflect the convergent evolution of this distinct mode of leaf morphogenesis in these distantly related plants. 相似文献
158.
The genomic organization and expression of genes of the T-cell receptor gamma (TRG) locus are described for mice and humans, but not for species such as rabbits (Oryctolagus cuniculus), in which T cells compose a sizeable proportion of T cells in the periphery. We cloned 200 kb of the rabbit TRG locus and determined the TRGV gene usage in adult and newborn rabbits by RT-PCR. We identified two TRGJ genes, one TRGC gene, and 22 TRGV genes, all of which encoded functional variable regions. One TRGV gene is the unique member of the TRGV2 subgroup, whereas the other genes belong to the TRGV1 subgroup. Evolutionary analyses of TRGV1 genes identified three distinct groups that can be explained by separate duplication events in the rabbit genome. Evidence of gene conversion between TRGV1.1 and TRGV1.6 was observed. Both TRGV1 and TRGV2 subgroup genes were expressed in the spleen, intestine, and appendix of adult rabbits, and the repertoire of TRGV genes expressed in these tissues was similar. In these tissues from newborns, and in skin from adults, only the genes from the TRGV1 subgroup were expressed. Greater TRGV-J junctional diversity was found in tissues from adult compared to newborn rabbits. Our analyses indicate rabbits have a larger germ line encoded TRG repertoire compared with that of mice and humans. In addition, we found TRGV gene usage is alike in most tissues of rabbits similar to that found in humans but in contrast to that found in mice.Electronic SupplementaryMaterial Supplementary material is available for this article at The nucleotide sequence data reported in this article have been submitted to GenBank and are assigned the accession numbers AY748325–AY748348 相似文献
159.
In the New Jersey Pinelands, severely disturbed areas often do not undergo a rapid succession to forest; rather, a patchy
cover of lichens, mosses and grasses persists for decades. We hypothesized that these plant covers affect soil microbial processes
in different ways, and that these effects may alter the successional dynamics of the patches. We predicted that the moss and
grass covers stimulate soil microbial activity, whereas lichens inhibit it, which may in turn inhibit succession. We collected
soil cores from beneath each type of cover plus bare soil within two types of highly disturbed areas—sites subjected to hot
wildfires, and areas mined for sand. Organic matter (OM) content, soil respiration and potential N mineralization were measured
in the cores. Soils under mosses were similar to those under grasses; they accumulated more OM and produced more mineral N,
predominantly in the form of ammonium, than either the bare soils or the soils beneath lichens. Mineralization under lichens,
like that of the bare soils but unlike the soils beneath mosses or grasses, was dominated by net nitrification. These patterns
were reproduced in experimentally transplanted moss and lichen mats. Mosses appear to create high-nutrient microsites via
high rates of OM accumulation and production of ammonium, whereas lichens maintain low-nutrient patches similar to bare soil
via low OM accumulation rates and production of mineral N predominantly in the mobile nitrate form. These differences in soil
properties may explain the lack of vascular plant invasion in lichen mats, in contrast to the moss-dominated areas. 相似文献
160.
Organisms living in arctic and alpine environments are increasingly impacted by human activities. To evaluate the potential impacts of global change, a better understanding of the demography of organisms in extreme environments is needed. In this study, we compare the age-specific demography of willow ptarmigan (Lagopus lagopus) breeding at arctic and subalpine sites, and white-tailed ptarmigan (L. leucurus) breeding at an alpine site. Rates of egg production improved with age at the alpine and subalpine sites, but the stochastic effects of nest and brood predation led to similar rates of annual fecundity among 1-, 2-, and 3+-year-old females. All populations had short generation times (T<2.7 years) and low net reproductive rates (R
0<1.2). Stable age distributions were weighted towards 1-year-old females in willow ptarmigan (>59%), and to 3+-year-old females in white-tailed ptarmigan (>47%). High damping ratios (ρ>3.2) indicated that asymptotic estimates were likely to match natural age distributions. Sensitivity and elasticity values indicated that changes in juvenile survival would have the greatest impact on the finite rate of population change (λ) in willow ptarmigan, whereas changes to the survival of 3+-year-old females would have a greater effect in white-tailed ptarmigan. High survivorship buffers white-tailed ptarmigan in alpine environments against the potential effects of climate change on annual fecundity, but may make the species more sensitive to the effects of pollutants or harvesting on adult survival. Conversely, processes that reduce annual fecundity would have a greater impact on the population viability of willow ptarmigan in arctic and subalpine environments. If these same demographic patterns prove to be widespread among organisms in extreme environments, it may be possible to develop general recommendations for conservation of the biological resources of arctic and alpine ecosystems. 相似文献