10,672 research outputs found
New Terms for the Compact Form of Electroweak Chiral Lagrangian
The compact form of the electroweak chiral Lagrangian is a reformulation of
its original form and is expressed in terms of chiral rotated electroweak gauge
fields, which is crucial for relating the information of underlying theories to
the coefficients of the low-energy effective Lagrangian. However the compact
form obtained in previous works is not complete. In this letter we add several
new chiral invariant terms to it and discuss the contributions of these terms
to the original electroweak chiral Lagrangian.Comment: 3 pages, references adde
Experimental Infection of Conventional Pigs with Streptococcus suis serotype 2 by Aerosolic Exposure
Infant arterial stiffness and maternal iron status in pregnancy: A UK birth cohort (Baby VIP study)
Background In animal studies, iron deficiency during pregnancy has been linked to increased offspring cardiovascular risk. No previous population studies have measured arterial stiffness early in life to examine its association with maternal iron status. Objective This study aimed to examine the association between maternal iron status in early pregnancy with infant brachio-femoral pulse wave velocity (PWV). Methods The Baby VIP (Baby’s Vascular health and Iron in Pregnancy) study is a UK-based birth cohort which recruited 362 women after delivery from the Leeds Teaching Hospitals postnatal wards. Ferritin and transferrin receptor levels were measured in maternal serum samples previously obtained in the first trimester. Infant brachio-femoral PWV was measured during a home visit at 2-6 weeks. Results Iron depletion (ferritin <15 ug/L) was detected in 79 (23%) women in early pregnancy. Infant PWV (m=6.7 m/s, sd=1.3, n=284) was not associated with maternal ferritin (adjusted change per 10 ug/L= 0.02, 95% CI -0.01, 0.1), nor with iron depletion (adjusted change = -0.2, 95% CI -0.6, 0.2). No evidence of association was observed between maternal serum transferrin receptor level or its ratio to ferritin with infant PWV. Maternal anaemia (<11 g/dL) at ≤20 weeks gestation was associated with a 1.0 m/s increase in infant PWV (adjusted 95% CI 0.1, 1.9). Conclusion This is the largest study to-date which assessed peripheral PWV as a measure of arterial stiffness in infants. There was no evidence of an association between markers of maternal iron status early in pregnancy and infant PWV
Gray's time-varying coefficients model for posttransplant survival of pediatric liver transplant recipients with a diagnosis of cancer
Transplantation is often the only viable treatment for pediatric patients with end-stage liver disease. Making well-informed decisions on when to proceed with transplantation requires accurate predictors of transplant survival. The standard Cox proportional hazards (PH) model assumes that covariate effects are time-invariant on right-censored failure time; however, this assumption may not always hold. Gray's piecewise constant time-varying coefficients (PC-TVC) model offers greater flexibility to capture the temporal changes of covariate effects without losing the mathematical simplicity of Cox PH model. In the present work, we examined the Cox PH and Gray PC-TVC models on the posttransplant survival analysis of 288 pediatric liver transplant patients diagnosed with cancer. We obtained potential predictors through univariable (P < 0.15) and multivariable models with forward selection (P < 0.05) for the Cox PH and Gray PC-TVC models, which coincide. While the Cox PH model provided reasonable average results in estimating covariate effects on posttransplant survival, the Gray model using piecewise constant penalized splines showed more details of how those effects change over time. © 2013 Yi Ren et al
LOS oligosaccharide modification enhances dendritic cell responses to meningococcal native outer membrane vesicles expressing a non toxic lipid A.
Outer membrane vesicles (OMV) are released by many bacteria, and contain immunogenic antigens in addition to harmful inflammatory factors, like lipopolysaccharides. Chemically detoxified OMV have been used in vaccines against Neisseria meningitidis (Nm), however little is known about their interaction with antigen presenting cells. In this study, we investigated the interaction of Nm OMV with human dendritic cells (DC) to gain further understanding of their biological activity. We engineered a novel serogroup B Nm that is unencapsulated (siaD), expresses pentacylated lipid A (lpxL1), hence conferring reduced toxicity, and expresses an lgtB oligosaccharide structure designed to target OMV to DC via DC-SIGN. We show that the lgtB moiety is critical for internalization of NOMV by DC. Furthermore, the lgtB moiety significantly enhances DC maturation, IL-10 and IL-23 production in the presence of a pentacylated lipid A. Whilst different DC phenotypes were observed for each NOMV, this had little effect on Th1 and Th2 cell differentiation, however lgtB significantly increased Th17 cell expansion in the presence of pentacylated lipid A. We believe that lgtB/lpxL1 NOMV should be considered further as a vaccine vector, particularly considering the importance of lgtB in antigen uptake and further human studies on antigen specific responses should be considered
A systematic analysis of experimental immunotherapies on tumors differing in size and duration of growth
We conducted a systematic analysis to determine the reason for the apparent disparity of success of immunotherapy between clinical and experimental cancers. To do this, we performed a search of PubMed using the keywords “immunotherapy” AND “cancer” for the years of 1980 and 2010. The midspread of experimental tumors used in all the relevant literature published in 2010 were between 0.5–121 mm3 in volume or had grown for four to eight days. Few studies reported large tumors that could be considered representative of clinical tumors, in terms of size and duration of growth. The predominant effect of cancer immunotherapies was slowed or delayed outgrowth. Regression of tumors larger than 200 mm3 was observed only after passive antibody or adoptive T cell therapy. The effectiveness of other types of immunotherapy was generally scattered. By comparison, very few publications retrieved by the 1980 search could meet our selection criteria; all of these used tumors smaller than 100 mm3, and none reported regression. In the entire year of 2010, only 13 used tumors larger than 400 mm3, and nine of these reported tumor regression. Together, these results indicate that most recent studies, using many diverse approaches, still treat small tumors only to report slowed or delayed growth. Nevertheless, a few recent studies indicate effective therapy against large tumors when using passive antibody or adoptive T cell therapy. For the future, we aspire to witness the increased use of experimental studies treating tumors that model clinical cancers in terms of size and duration of growth
Functional organisation for verb generation in children with developmental language disorder
Developmental language disorder (DLD) is characterised by difficulties in learning one's native language for no apparent reason. These language difficulties occur in 7% of children and are known to limit future academic and social achievement. Our understanding of the brain abnormalities associated with DLD is limited. Here, we used a simple four-minute verb generation task (children saw a picture of an object and were instructed to say an action that goes with that object) to test children between the ages of 10–15 years (DLD N = 50, typically developing N = 67). We also tested 26 children with poor language ability who did not meet our criteria for DLD. Contrary to our registered predictions, we found that children with DLD did not have (i) reduced activity in language relevant regions such as the left inferior frontal cortex; (ii) dysfunctional striatal activity during overt production; or (iii) a reduction in left-lateralised activity in frontal cortex. Indeed, performance of this simple language task evoked activity in children with DLD in the same regions and to a similar level as in typically developing children. Consistent with previous reports, we found sub-threshold group differences in the left inferior frontal gyrus and caudate nuclei, but only when analysis was limited to a subsample of the DLD group (N = 14) who had the poorest performance on the task. Additionally, we used a two-factor model to capture variation in all children studied (N = 143) on a range of neuropsychological tests and found that these language and verbal memory factors correlated with activity in different brain regions. Our findings indicate a lack of support for some neurological models of atypical language learning, such as the procedural deficit hypothesis or the atypical lateralization hypothesis, at least when using simple language tasks that children can perform. These results also emphasise the importance of controlling for and monitoring task performance
Lymphangiogenesis in myocardial remodelling after infarction
Ishikawa Y, Akishima-Fukasawa Y, Ito K, Akasaka Y, Tanaka M, Shimokawa R, Kimura-Matsumoto M, Morita H, Sato S, Kamata I & Ishii T (2007) Histopathology51, 345–35
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