2,350 research outputs found
IFPA meeting 2015 workshop report IV: placenta and obesity; stem cells of the feto-maternal interface; placental immunobiology and infection
No full textAbstract not availableM.H. Abumaree, A. Almutairi, S. Cash, P. Boeuf, L.W. Chamley, T. Gamage, J.L. James, B. Kalionis, T.Y. Khong, K.S. Kolahi, R. Lim, S. Liong, T.K. Morgan, K. Motomura, H.N. Peiris, R.A. Pelekanos, E. Pelzer, A. Shafiee, G.E. Lash, D. Natal
T Cell responses to whole SARS Coronavirus in humans
No full textEffective vaccines should confer long-term protection against future outbreaks of severe acute respiratory syndrome (SARS) caused by a novel zoonotic coronavirus (SARS-CoV) with unknown animal reservoirs. We conducted a cohort study examining multiple parameters of immune responses to SARS-CoV infection, aiming to identify the immune correlates of protection. We used a matrix of overlapping peptides spanning whole SARS-CoV proteome to determine T cell responses from 128 SARS convalescent samples by ex vivo IFN-γ ELISPOT assays. Approximately 50% of convalescent SARS patients were positive for T cell responses, and 90% possessed strongly neutralizing Abs. Fifty-five novel T cell epitopes were identified, with spike protein dominating total T cell responses. CD8+ T cell responses were more frequent and of a greater magnitude than CD4+ T cell responses (p < 0.001).
Polychromatic cytometry analysis indicated that the virus-specific T cells from the severe group tended to be a central memory phenotype (CD27+/CD45RO+) with a significantly higher frequency of polyfunctional CD4+ T cells producing IFN-γ, TNF-α, and IL-2, and CD8+ T cells producing IFN-γ, TNF-α, and CD107a (degranulation), as compared with the mild-moderate group. Strong T cell responses correlated significantly (p < 0.05) with higher neutralizing Ab. The serum cytokine profile during acute infection indicated a significant elevation of innate immune responses. Increased Th2 cytokines were observed in patients with fatal infection. Our study provides a roadmap for the immunogenicity of SARS-CoV and types of immune responses that may be responsible for the virus clearance, and should serve as a benchmark for SARS-CoV vaccine design and evaluation
Building Materials from Colloidal Nanocrystal Arrays: Evolution of Structure, Composition, and Mechanical Properties upon the Removal of Ligands by O-2 Plasma
No full textMinimally parametric power spectrum reconstruction from the Lyman-alpha Forest
No full textCurrent results from the Lyman α forest assume that the primordial power spectrum of density perturbations follows a simple power-law form. We present the first analysis of Lyman α data to study the effect of relaxing this strong assumption on primordial and astrophysical constraints. We perform a large suite of numerical simulations, using them to calibrate a minimally parametric framework for describing the power spectrum. Combined with cross-validation, a statistical technique which prevents overfitting of the data, this framework allows us to reconstruct the power spectrum shape without strong prior assumptions. We find no evidence for deviation from scale-invariance; our analysis also shows that current Lyman α data do not have sufficient statistical power to robustly probe the shape of the power spectrum at these scales. In contrast, the ongoing Baryon Oscillation Sky Survey will be able to do so with high precision. Furthermore, this near-future data will be able to break degeneracies between the power spectrum shape and astrophysical parameters
State space modeling of Gegenbauer processes with long memory
No full textAn approximation of a Gegenbauer autoregressive moving average (GARMA) process with long memory using a finite order moving average (MA) representation is considered. The state space form of the MA approximation is developed and the corresponding estimates are obtained by pseudo maximum likelihood using the Kalman filter. For comparative purposes the same exercise is executed with an autoregressive (AR) approximation. Using an extensive Monte Carlo experiment, optimal order of the chosen MA approximation is established, and found it was not very large (around 35) and rather insensitive to the sample size. Further evidence suggests the approximation is reliable for forecasting and signal extraction with periodic long memory components. A rolling forecasting experiment was performed to validate the choice of optimal order of both AR and MA approximations in terms of predictive accuracy. Finally, the proposed methodology was applied to two yearly sunspots time series, and compared with corresponding results proposed in the literature
The presence of 5-HT in myenteric varicosities is not due to uptake of 5-HT released from the mucosa during dissection: use of a novel method for quantifying 5-HT immunoreactivity in myenteric ganglia
No full textAuthor version made available according to Publisher copyright policy. This is the accepted version of the following article:
Keating, D. J., Peiris, H., Kyloh, M., Brookes, S. J. H. and Spencer, N. J. (2013), The presence of 5-HT in myenteric varicosities is not due to uptake of 5-HT released from the mucosa during dissection: use of a novel method for quantifying 5-HT immunoreactivity in myenteric ganglia. Neurogastroenterology & Motility, 25: 849–853,
which has been published in final form at
http://dx.doi.org/10.1111/nmo.12189.
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Supplemental Material, sj-pdf-1-vet-10.1177_03009858211043084 - Cellular tropism of SARS-CoV-2 in the respiratory tract of Syrian hamsters and B6.Cg-Tg(K18-ACE2)2Prlmn/J transgenic mice
No full textSupplemental Material, sj-pdf-1-vet-10.1177_03009858211043084 for Cellular tropism of SARS-CoV-2 in the respiratory tract of Syrian hamsters and B6.Cg-Tg(K18-ACE2)2Prlmn/J transgenic mice by Hui-Ling Yen, Sophie Valkenburg, Sin Fun Sia, Ka Tim Choy, J. S. Malik Peiris, Karen H. M. Wong, Nicholas Crossland, Florian Douam and John M. Nicholls in Veterinary Pathology</p
The M, E, and N structural proteins of the severe acute respiratory syndrome coronavirus are required for efficient assembly, trafficking, and release of virus-like particles
No full textCopyright @ 2008 American Society for Microbiology.The production of virus-like particles (VLPs) constitutes a relevant and safe model to study molecular determinants of virion egress. The minimal requirement for the assembly of VLPs for the coronavirus responsible for severe acute respiratory syndrome in humans (SARS-CoV) is still controversial. Recent studies have shown that SARS-CoV VLP formation depends on either M and E proteins or M and N proteins. Here we show that both E and N proteins must be coexpressed with M protein for the efficient production and release of VLPs by transfected Vero E6 cells. This suggests that the mechanism of SARS-CoV assembly differs from that of other studied coronaviruses, which only require M and E proteins for VLP formation. When coexpressed, the native envelope trimeric S glycoprotein is incorporated onto VLPs. Interestingly, when a fluorescent protein tag is added to the C-terminal end of N or S protein, but not M protein, the chimeric viral proteins can be assembled within VLPs and allow visualization of VLP production and trafficking in living cells by state-of-the-art imaging technologies. Fluorescent VLPs will be used further to investigate the role of cellular machineries during SARS-CoV egress.The University of Hong Kong and the French Ministry of Health
Epizootiological survey of Trichinella spp. infection in carnivores, rodents and insectivores in Hokkaido, Japan.
No full textIn order to evaluate the present epidemiological situation of Trichinella infection in wild animals in Hokkaido, Japan, red foxes (Vulpes vulpes), raccoon dogs (Nyctereutes procyonoides) , brown bears (Ursus arctos) , martens (Martes melampus), rodents and insectivores captured in Hokkaido were examined for muscle larvae by the artificial digestion method from 2000 to 2006. Foxes (44/319, 13.8%), raccoon dogs (6/77, 7.8%) and brown bears (4/126, 3.2%) were found to be infected with Trichinella larvae and all other animal species evaluated were negative. Multiplex PCR and DNA sequencing revealed that larvae from a fox captured in Otofuke, in south-eastern Hokkaido, were T. nativa, and larvae from 27 animals including 21 foxes, 2 raccoon dogs and 4 brown bears captured in western Hokkaido were Trichinella T9
H5N1 Clade 2.2 Polymorphism Tracing Identifies Influenza Recombination and Potential Vaccine Targets
No full textHighly pathogenic Influenza A H5N1 was first identified in Guangdong Province in 1996, followed by human cases in Hong Kong in 1997 1. The number of confirmed human cases now exceeds 300 and the associated Case Fatality Rate exceeds 60% 2. The genetic diversity of the serotype continues to increase. Four distinct clades or sub-clades have been linked to human cases 3.4. The gradual genetic changes identified in the sub-clades have been attributed to copy errors by viral encoded polymerases that lack an editing function, thereby resulting in antigenic drift 5. We traced polymorphism acquisition in Clade 2.2 sequences. We report here the concurrent acquisition of the same polymorphism by multiple, genetically distinct, Clade 2.2 sub-clades in Egypt, Russia and Ghana. These changes are not easily explained by the current theory of “random mutation” through copy error, and are more easily explained by recombination with a common source. This conclusion is supported by additional polymorphisms shared by Clade 2.2 isolates in Egypt, Nigeria and Germany including aggregation of regional polymorphisms from each of these areas into a single Nigerian human hemagglutinin gene
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