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.

Plasmodium falciparum rosetting is associated with malaria severity in Kenya.

Abstract: Rosette formation in 154 fresh Plasmodium falciparum isolates from Kenyan children with mild (n 5 54), moderate (n 564), or severe (n 536) malaria was studied to determine whether the ability to form rosettes in vitro is correlated with malaria severity. There was a wide distribution of rosette frequencies within each clinical category; however, a clear trend towards higher rosette frequency with increasing severity of disease wasseen,withthemedianrosettefrequencyofthemild-malariagroup(1%;range,0to82%)beingsignificantly lowerthanthoseofthemoderate-malariagroup(5%;range,0to45%;Mann-WhitneyUtest,P<0.02)andthe severe-malaria group (7%; range, 0 to 97%; Mann-Whitney U test, P < 0.003). Within the severe-malaria category there was no difference in rosetting among isolates from cerebral malaria patients or those with other forms of severe malaria. We also examined the ABO blood groups of the patients from whom isolates were obtained and found that isolates from group O patients (median rosette frequency, 2%; range 0 to 45%) rosetted less well than those from group A (median, 7%; range 0 to 82%; Mann-Whitney U test,P< 0.01) or group AB (median, 11%; range 0 to 94%; Mann-Whitney U test,P< 0.03). We therefore confirm that rosetting isassociatedwithseveremalariaandprovidefurtherevidencethatrosettingisinfluencedbyABObloodgroup type. Whether rosetting itself plays a direct role in the pathogenesis of severe malaria or is a marker for some other causal factor remains unknown. Plasmodium falciparummalaria remains a common cause of morbidity and mortality throughout the tropical regions of the world and is estimated to cause 1 million deaths a year in Africa alone (6). Although infection with malaria parasites is common, only 1 to 2% of infections lead to severe life-threatening disease characterized by a range of clinical features, including unrousable coma (cerebral malaria), severe anemia, metabolic acidosis, and multiorgan failure (25). The majority of malarial deaths in Africa occur in children under 5 years of age, as with increasing age and recurrent exposure to malaria a nonsterile immunity develops (14). It remains unclear why some children develop the severe manifestations of disease while others suffer only mild symptoms or remain asymptomatic.

Non-contrast T1-mapping detects acute myocardial edema with high diagnostic accuracy: a comparison to T2-weighted cardiovascular magnetic resonance

Abstract: T2w-CMR is used widely to assess myocardial edema. Quantitative T1-mapping is also sensitive to changes in free water content. We hypothesized that T1-mapping would have a higher diagnostic performance in detecting acute edema than dark-blood and bright-blood T2w-CMR. We investigated 21 controls (55 ± 13 years) and 21 patients (61 ± 10 years) with Takotsubo cardiomyopathy or acute regional myocardial edema without infarction. CMR performed within 7 days included cine, T1-mapping using ShMOLLI, dark-blood T2-STIR, bright-blood ACUT2E and LGE imaging. We analyzed wall motion, myocardial T1 values and T2 signal intensity (SI) ratio relative to both skeletal muscle and remote myocardium. All patients had acute cardiac symptoms, increased Troponin I (0.15-36.80 ug/L) and acute wall motion abnormalities but no LGE. T1 was increased in patient segments with abnormal and normal wall motion compared to controls (1113 ± 94 ms, 1029 ± 59 ms and 944 ± 17 ms, respectively; p < 0.001). T2 SI ratio using STIR and ACUT2E was also increased in patient segments with abnormal and normal wall motion compared to controls (all p < 0.02). Receiver operator characteristics analysis showed that T1-mapping had a significantly larger area-under-the-curve (AUC = 0.94) compared to T2-weighted methods, whether the reference ROI was skeletal muscle or remote myocardium (AUC = 0.58-0.89; p < 0.03). A T1 value of greater than 990 ms most optimally differentiated segments affected by edema from normal segments at 1.5 T, with a sensitivity and specificity of 92 %. Non-contrast T1-mapping using ShMOLLI is a novel method for objectively detecting myocardial edema with a high diagnostic performance. T1-mapping may serve as a complementary technique to T2-weighted imaging for assessing myocardial edema in ischemic and non-ischemic heart disease, such as quantifying area-at-risk and diagnosing myocarditis.

Complementary localization and lateralization of orienting and motor attention

Abstract: It is widely agreed that the right posterior parietal cortex has a preeminent role in visuospatial and orienting attention. A number of lines of evidence suggest that although orienting and the preparation of oculomotor responses are dissociable from each other, the two are intimately related. If this is true, then it should be possible to identify other attentional mechanisms tied to other response modalities. We used repetitive transcranial magnetic stimulation (rTMS) to demonstrate the existence of a distinct anterior parietal mechanism of motor attention. The critical area for motor attention is anterior to the one concerned with orienting, and it is lateralized to the left hemisphere in humans.

Longitudinal Analysis of CD8+ T Cells Specific for Structural and Nonstructural Hepatitis B Virus Proteins in Patients with Chronic Hepatitis B: Implications for Immunotherapy

Abstract: The cytotoxic T-cell response in chronic hepatitis B virus (HBV) infection has been described as weak and mono- or oligospecific in comparison to the more robust virus-specific T-cell response present in resolved infection. However, chronic hepatitis B is a heterogeneous disease with markedly variable levels of virus replication and liver disease activity. Here we analyzed (both directly ex vivo and after in vitro stimulation) the HBV-specific CD8 T-cell responses against structural and nonstructural HBV proteins longitudinally in patients with different patterns of chronic infections. We found that the profiles of virus-specific CD8(+)-T-cell responses during chronic infections are highly heterogeneous and influenced more by the level of HBV replication than by the activity of liver disease. An HBV DNA load of 10(7) copies) of HBV replication. These findings have implications for the design of immunotherapy for chronic HBV infections.

Preterm heart in adult life: cardiovascular magnetic resonance reveals distinct differences in left ventricular mass, geometry, and function.

Abstract: Background—Preterm birth leads to an early switch from fetal to postnatal circulation before completion of left ventricular in utero development. In animal studies, this results in an adversely remodeled left ventricle. We determined whether preterm birth is associated with a distinct left ventricular structure and function in humans. Methods and Results—A total of 234 individuals 20 to 39 years of age underwent cardiovascular magnetic resonance. One hundred two had been followed prospectively since preterm birth (gestational age=30.3±2.5 week; birth weight=1.3±0.3 kg), and 132 were born at term to uncomplicated pregnancies. Longitudinal and short-axis cine images were used to quantify left ventricular mass, 3-dimensional geometric variation by creation of a unique computational cardiac atlas, and myocardial function. We then determined whether perinatal factors modify these left ventricular parameters. Individuals born preterm had increased left ventricular mass (66.5±10.9 versus 55.4±11.4 g/m2; P<0.001)...