John Radcliffe Hospital

About: John Radcliffe Hospital is a healthcare organization based out in Oxford, Oxfordshire, United Kingdom. It is known for research contribution in the topics: Population & Antigen. The organization has 14491 authors who have published 23670 publications receiving 1459015 citations.

Prenatal diagnosis of coarctation of the aorta improves survival and reduces morbidity

Abstract: Objective: To investigate whether antenatal diagnosis of coarctation of the aorta results in reduced mortality and improved preoperative haemodynamic stability compared with postnatal diagnosis. Design: Retrospective review of all cases of coarctation of the aorta presenting to a tertiary fetal and neonatal cardiology service from January 1994 to December 1998. Methods: Prenatal, postnatal, and necropsy records were reviewed to determine survival in the two groups. Markers of preoperative illness severity were recorded, including presence of femoral pulse, collapse, left ventricular function, ductal patency on echocardiography, coagulation status, duration of intensive care unit and total hospital stay, heart rate, respiratory rate, plasma creatinine, plasma potassium, and right upper limb blood pressure. A univarate and multivariate analysis was conducted on all variables and a cumulative score was created and subjected to logistic regression analysis. Results: Both collapse and death were more common in the postnatally diagnosed group (p < 0.05). Femoral pulses were more likely to be palpable and there was echocardiographic evidence of duct patency in the antenatally diagnosed infants (p < 0.001 and p < 0.05, respectively). An increased respiratory rate was associated with postnatal presentation (p < 0.05). Infants with haemodynamic instability preoperatively were more likely to have been diagnosed postnatally (p < 0.01). Conclusions: Antenatal diagnosis of coarctation of the aorta is associated with improved survival and preoperative clinical condition.

MAIT cells are activated during human viral infections

Abstract: Mucosal-associated invariant T (MAIT) cells are abundant in humans and recognize bacterial ligands. Here, we demonstrate that MAIT cells are also activated during human viral infections in vivo. MAIT cells activation was observed during infection with dengue virus, hepatitis C virus and influenza virus. This activation-driving cytokine release and Granzyme B upregulation-is TCR-independent but dependent on IL-18 in synergy with IL-12, IL-15 and/or interferon-α/β. IL-18 levels and MAIT cell activation correlate with disease severity in acute dengue infection. Furthermore, HCV treatment with interferon-α leads to specific MAIT cell activation in vivo in parallel with an enhanced therapeutic response. Moreover, TCR-independent activation of MAIT cells leads to a reduction of HCV replication in vitro mediated by IFN-γ. Together these data demonstrate MAIT cells are activated following viral infections, and suggest a potential role in both host defence and immunopathology.

The genome of the simian and human malaria parasite Plasmodium knowlesi

Abstract: Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the 'kra' monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia. Plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated, and it has a close phylogenetic relationship to Plasmodium vivax, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood cell preference, absence of a dormant liver stage or 'hypnozoite' in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone) nuclear genome sequence. This is the first monkey malaria parasite genome to be described, and it provides an opportunity for comparison with the recently completed P. vivax genome and other sequenced Plasmodium genomes. In contrast to other Plasmodium genomes, putative variant antigen families are dispersed throughout the genome and are associated with intrachromosomal telomere repeats. One of these families, the KIRs, contains sequences that collectively match over one-half of the host CD99 extracellular domain, which may represent an unusual form of molecular mimicry.

Quantum dot semiconductor nanocrystals for immunophenotyping by polychromatic flow cytometry

Abstract: Immune responses arise from a wide variety of cells expressing unique combinations of multiple cell-surface proteins. Detailed characterization is hampered, however, by limitations in available probes and instrumentation. Here, we use the unique spectral properties of semiconductor nanocrystals (quantum dots) to extend the capabilities of polychromatic flow cytometry to resolve 17 fluorescence emissions. We show the need for this power by analyzing, in detail, the phenotype of multiple antigen-specific T-cell populations, revealing variations within complex phenotypic patterns that would otherwise remain obscure. For example, T cells specific for distinct epitopes from one pathogen, and even those specific for the same epitope, can have markedly different phenotypes. The technology we describe, encompassing the detection of eight quantum dots in conjunction with conventional fluorophores, should expand the horizons of flow cytometry, as well as our ability to characterize the intricacies of both adaptive and innate cellular immune responses.