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121.
Kathie A. Mihindukulasuriya Nang L. Nguyen Guang Wu Henry V. Huang Amelia P. A. Travassos da Rosa Vsevolod L. Popov Robert B. Tesh David Wang 《Journal of virology》2009,83(10):5109-5116
Here, we report the sequencing and classification of Nyamanini virus (NYMV) and Midway virus (MIDWV), two antigenically related viruses that were first isolated in 1957 and 1966, respectively. Although these viruses have been cultured multiple times from cattle egrets, seabirds, and their ticks, efforts to classify them taxonomically using conventional serological and electron microscopic approaches have failed completely. We used a random shotgun sequencing strategy to define the genomes of NYMV and MIDWV. Contigs of 11,631 and 11,752 nucleotides, representing the complete genome of NYMV and the near-complete genome of MIDWV, respectively, were assembled. Each virus genome was predicted to carry six open reading frames (ORFs). BLAST analysis indicated that only two of the ORF proteins of each virus, the putative nucleocapsid and polymerase, had detectable sequence similarity to known viral proteins. Phylogenetic analysis of these ORF proteins demonstrated that the closest relatives of NYNV and MIDWV are negative-stranded-RNA viruses in the order Mononegavirales. On the basis of their very limited sequence similarity to known viruses, we propose that NYMV and MIDWV define a novel genus, Nyavirus, in this order.Nyamanini virus (NYMV) was first isolated in 1957 from a cattle egret (Bubulcus ibis) in South Africa (24). It has subsequently been isolated in Nigeria, Egypt, India, and Thailand from cattle egrets and Argas walkerae ticks (14, 16, 24). Although there has been no recognized human infection or disease associated with NYMV, suckling mice succumbed to NYMV infection 7 or 8 days after intracerebral inoculation (14). NYMV has not been definitively characterized or classified to date (10).Midway virus (MIDWV) was first isolated in 1966 from seabird ticks of two species [Ornithodoros (Alectorobius) spp.] collected on the Midway, Kure, and Manana islands in the Central Pacific and from northern Honshu, Japan. In addition, on Aomatsushima Island, nestling seabirds of two seabird species, Larus crassirostris and Nycticorax nycticorax, were found to have antibody to MIDWV. This virus is pathogenic for newborn Swiss mice but not 4-week-old Swiss mice injected intracranially. Also, the virus is cytopathic in BHK-21 cells and produces plaques in Vero cells. Efforts to classify MIDWV have revealed only that MIDWV is antigenically related to NYMV in cross-box complement fixation (CF) assays (22).To date, conventional approaches, such as serological analysis and electron microscopy (EM), have not yielded definitive characterization of MIDWV or NYMV. Heretofore, it was not known whether MIDWV and NYMV are DNA viruses or RNA viruses or to which virus family they belong. In this paper, we describe the application of unbiased high-throughput sequencing to define the genome sequences of NYMV and MIDWV. By analysis of their genomes, NYMV and MIDWV were determined to be negative-stranded RNA viruses highly divergent from all known viruses but most closely related to viruses in the order Mononegavirales. On the basis of the analysis presented herein, we propose that NYMV and MIDWV define a novel taxon within the order Mononegavirales. 相似文献
122.
Debbie Guatelli‐Steinberg Rebecca J. Ferrell Jennifer Spence Tiffany Talabere Amelia Hubbard Stacey Schmidt 《American journal of physical anthropology》2009,140(2):216-233
Previous research has demonstrated that great ape and macaque males achieve large canine crown sizes primarily through extended canine growth periods. Recent work has suggested, however, that platyrrhine males may achieve larger canine sizes by accelerating rather than prolonging growth. This study tested the hypothesis that the ontogenetic pathway leading to canine sexual dimorphism in catarrhines differs from that of platyrrhines. To test this hypothesis, males and females of several catarrhine genera (Hylobates, Papio, Macaca, Cercopithecus, and Cercocebus) and three platyrrhine genera (Cebus, Ateles, and Callicebus) were compared in the number and spacing of perikymata (enamel growth increments) on their canine crowns. In addition, perikymata periodicities (the number of days of growth perikymata represent) were determined for five genera (Hylobates, Papio, Macaca, Cebus, and Ateles) using previously published as well as original data gathered for this study. The central findings are as follows: 1) males have more perikymata than females for seven of eight genera (in five of the seven, the differences are statistically significant); 2) in general, the greater the degree of sexual dimorphism, the greater the sex difference in male and female perikymata numbers; 3) there is no evidence of a systematic sex difference in primate periodicities; and 4) there is some evidence that sex differences in enamel formation rates may make a minor contribution to canine sexual dimorphism in Papio and Cercopithecus. These findings strongly suggest that in both catarrhines and platyrrhines prolongation of male canine growth is the primary mechanism by which canine crown sexual dimorphism is achieved. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
123.
Verónica Veses Manuel Casanova Amelia Murgui Neil A.R. Gow & José P. Martínez 《FEMS yeast research》2009,9(2):293-300
The human fungal pathogen Candida albicans undergoes reversible morphogenetic transitions between yeast, hyphal and pseudohyphal forms. The fungal vacuole actively participates in differentiation processes and plays a key role supporting hyphal growth. The ABG1 gene of C. albicans encodes an essential protein located in the vacuolar membranes of both yeast and hyphae. Using fluorescence microscopy of a green fluorescent protein-tagged version of Abg1p, a fraction of the protein was detected in hyphal tips, not associated with vacuolar membranes. Live cell imaging of emerging germ tubes showed that Abg1p migrated to the polarized growth site and colocalized with endocytic vesicles. Phenotypic analysis of a methionine-regulated conditional mutant confirmed that Abg1p is involved in endocytosis. 相似文献
124.
DNase expression allows the pathogen group A Streptococcus to escape killing in neutrophil extracellular traps 总被引:1,自引:0,他引:1
Buchanan JT Simpson AJ Aziz RK Liu GY Kristian SA Kotb M Feramisco J Nizet V 《Current biology : CB》2006,16(4):396-400
The innate immune response plays a crucial role in satisfactory host resolution of bacterial infection. In response to chemotactic signals, neutrophils are early responding cells that migrate in large numbers to sites of infection. The recent discovery of secreted neutrophil extracellular traps (NETs) composed of DNA and histones opened a novel dimension in our understanding of the microbial killing capacity of these specialized leukocytes. M1 serotype strains of the pathogen Group A Streptococcus (GAS) are associated with invasive infections including necrotizing fasciitis (NF) and express a potent DNase (Sda1). Here we apply a molecular genetic approach of allelic replacement mutagenesis, single gene complementation, and heterologous expression to demonstrate that DNase Sda1 is both necessary and sufficient to promote GAS neutrophil resistance and virulence in a murine model of NF. Live fluorescent microscopic cell imaging and histopathological analysis are used to establish for the first time a direct linkage between NET degradation and bacterial pathogenicity. Inhibition of GAS DNase activity with G-actin enhanced neutrophil clearance of the pathogen in vitro and reduced virulence in vivo. The results demonstrate a significant role for NETs in neutrophil-mediated innate immunity, and at the same time identify a novel therapeutic target against invasive GAS infection. 相似文献
125.
126.
Serrano-Sánchez JA Delgado-Guerra S Olmedillas H Guadalupe-Grau A Arteaga-Ortiz R Sanchis-Moysi J Dorado C Calbet JA 《PloS one》2010,5(10):e13435
Background
To determine if there is an association between physical activity assessed by the short version of the International Physical Activity Questionnaire (IPAQ) and cardiorespiratory and muscular fitness.Methodology/Principal Findings
One hundred and eighty-two young males (age range: 20–55 years) completed the short form of the IPAQ to assess physical activity. Body composition (dual-energy X-Ray absorptiometry), muscular fitness (static and dynamic muscle force and power, vertical jump height, running speed [30 m sprint], anaerobic capacity [300 m running test]) and cardiorespiratory fitness (estimated VO2max: 20 m shuttle run test) were also determined in all subjects.Activity-related energy expenditure of moderate and vigorous intensity (EEPAmoderate and EEPAvigorous, respectively) was inversely associated with indices of adiposity (r = −0.21 to −0.37, P<0.05). Cardiorespiratory fitness (VO2max) was positively associated with LogEEPAmoderate (r = 0.26, P<0.05) and LogEEPAvigorous (r = 0.27). However, no association between VO2max with LogEEPAmoderate, LogEPPAvigorous and LogEEPAtotal was observed after adjusting for the percentage of body fat. Multiple stepwise regression analysis to predict VO2max from LogEEPAwalking, LogEEPAmoderate, LogEEPAvigorous, LogEEPAtotal, age and percentage of body fat (%fat) showed that the %fat alone explained 62% of the variance in VO2max and that the age added another 10%, while the other variables did not add predictive value to the model [VO2max = 129.6−(25.1× Log %fat) − (34.0× Log age); SEE: 4.3 ml.kg−1. min−1; R2 = 0.72 (P<0.05)]. No positive association between muscular fitness-related variables and physical activity was observed, even after adjusting for body fat or body fat and age.Conclusions/Significance
Adiposity and age are the strongest predictors of VO2max in healthy men. The energy expended in moderate and vigorous physical activities is inversely associated with adiposity. Muscular fitness does not appear to be associated with physical activity as assessed by the IPAQ. 相似文献127.
128.
Peptoids, oligomers of N-substituted glycine, have been valuable targets for study and diverse application as peptidomimetics and as nanomaterials. Their conformational heterogeneity has made the study of peptoid structures using high-resolution analyses challenging, limiting our understanding of the physiochemical features that mediate peptoid folding. Here, we introduce a new method for the study of peptoid structure that relies on the environmentally sensitive fluorescence properties of 4-N,N-dimethylamino-1,8-naphthalimide (4-DMN). We have prepared a 4-DMN-functionalized primary amine that is compatible with the traditional submonomer peptoid synthesis methods and incorporated it sequence-specifically into 11 of 13 new peptoids. When included as a peptoid side chain modification, the fluorescence emission intensity of 4-DMN correlates with predictions of the fluorophore's local polarity within a putative structure. 4-DMN fluorescence is maximized when the fluorophore is placed in the middle of the hydrophobic face of an amphiphilic helical peptoid. When the fluorophore is placed near the peptoid terminus or on a polar face of an amphiphilic sequence, 4-DMN fluorescence is diminished. Disruption of the peptoid secondary structure or amphiphilicity also modulates 4-DMN fluorescence. The peptoids' helical secondary structures are moderately disrupted by inclusion of a 4-DMN-modified side chain as evaluated by changes in the peptoids' CD spectral features. This new method for peptoid structure evaluation should be a valuable complement to existing peptoid structural analysis tools. 相似文献
129.
Guerra B Olmedillas H Guadalupe-Grau A Ponce-González JG Morales-Alamo D Fuentes T Chapinal E Fernández-Pérez L De Pablos-Velasco P Santana A Calbet JA 《Journal of applied physiology (Bethesda, Md. : 1985)》2011,111(3):715-725
This study was designed to determine whether sprint exercise activates signaling cascades linked to leptin actions in human skeletal muscle and how this pattern of activation may be interfered by glucose ingestion. Muscle biopsies were obtained in 15 young healthy men in response to a 30-s sprint exercise (Wingate test) randomly distributed into two groups: the fasting (n = 7, C) and the glucose group (n = 8, G), who ingested 75 g of glucose 1 h before the Wingate test. Exercise elicited different patterns of JAK2, STAT3, STAT5, ERK1/2, p38 MAPK phosphorylation, and SOCS3 protein expression during the recovery period after glucose ingestion. Thirty minutes after the control sprint, STAT3 and ERK1/2 phosphorylation levels were augmented (both, P < 0.05). SOCS3 protein expression was increased 120 min after the control sprint but PTP1B protein expression was unaffected. Thirty and 120 min after the control sprint, STAT5 phosphorylation was augmented (P < 0.05). Glucose abolished the 30 min STAT3 and ERK1/2 phosphorylation and the 120 min SOCS3 protein expression increase while retarding the STAT5 phosphorylation response to sprint. Activation of these signaling cascades occurred despite a reduction of circulating leptin concentration after the sprint. Basal JAK2 and p38 MAPK phosphorylation levels were reduced and increased (both P < 0.05), respectively, by glucose ingestion prior to exercise. During recovery, JAK2 phosphorylation was unchanged and p38 MAPK phosphorylation was transiently reduced when the exercise was preceded by glucose ingestion. In conclusion, sprint exercise performed under fasting conditions is a leptin signaling mimetic in human skeletal muscle. 相似文献