1,056 research outputs found
Soluble gC1qR is an autocrine signal that induces B1R expression on endothelial cells
Bradykinin (BK) is one of the most potent vasodilator agonists known and belongs to the kinin family of proinflammatory peptides. BK induces its activity via two G protein-coupled receptors: BK receptor 1 (B1R) and BK receptor 2. Although BK receptor 2 is constitutively expressed on endothelial cells (ECs), B1R is induced by IL-1β. The C1q receptor, receptor for the globular heads of C1q (gC1qR), which plays a role in BK generation, is expressed on activated ECs and is also secreted as soluble gC1qR (sgC1qR). Because sgC1qR can bind to ECs, we hypothesized that it may also serve as an autocrine/paracrine signal for the induction of B1R expression. In this study, we show that gC1qR binds to ECs via a highly conserved domain consisting of residues 174-180, as assessed by solid-phase binding assay and deconvolution fluorescence microscopy. Incubation of ECs (24 h, 37°C) with sgC1qR resulted in enhancement of B1R expression, whereas incubation with gC1qR lacking aa 174-180 and 154-162 had a diminished effect. Binding of sgC1qR to ECs was through surface-bound fibrinogen and was inhibited by anti-fibrinogen. In summary, our data suggest that, at sites of inflammation, sgC1qR can enhance vascular permeability by upregulation of B1R expression through de novo synthesis, as well as rapid translocation of preformed B1R
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Semiparametric Single-index Predictive Regression
This paper studies a semiparametric single-index predictive regression model with multiple nonstationary predictors that exhibit co-movement behaviour. Orthogonal series expansion is employed to approximate the unknown link function in the model and the estimator is derived from an optimization under constraint. The main finding includes two types of super-consistency rates for the estimators of the index parameter. The central limit theorem is established for a plug-in estimator of the unknown link function. In the empirical studies, we provide ample evidence in favor of nonlinear predictability of the stock return using four pairs of nonstationary predictors
Point mutations of the P53 gene, human hepatocellular carcinoma and aflatoxins
The tumor suppressor p53 exerts important protective functions towards DNA-damaging agents. Its inactivation by allelic deletions or point mutations within the P53 gene as well as complex formation of wildtype p53 with cellular or viral proteins is a common and crucial event in carcinogenesis. Mutations increase the half-life of the p53 protein allowing the immunohistochemical detection and anti-p53 antibody formation. Distinct G to T point mutations in codon 249 leading to a substitution of the basic amino acid arginine by the neutral amino acid serin are responsible for the altered functionality of the mutant gene product and were originally identified in 8 of 16 Chinese and 5 of 10 African HCC patients. Both groups are frequently exposed to mycotoxin contaminations of their food. Today an average P53 gene mutation rate of 25% is assumed for high-aflatoxin B1-exposure regions. This is double the rate observed in low-aflatoxin B1-exposure countries. Although many HCC patients displaying P53 mutations also suffer from HBV infection, which itself can lead to rearrangements of P53 coding regions or induce the synthesis of viral proteins possibly interacting with p53, the specific G to T transversion within codon 249 of the P53 gene seems to directly reflect the extent of aflatoxin B1 exposure
Difference in astringency of the main pea protein fractions
Interactions between food and saliva govern complex mouthfeel perceptions such as astringency. Herein, we present a study of the interactions of salivary proteins with the main pea protein fractions that are obtained by isoelectric and salt precipitation (legumin-rich, vicilin-rich and albumin-rich fractions). The sensory evaluations performed on protein solutions by trained panelists evidenced that all three protein fractions exhibit a basal level of astringency, but that the albumin fraction was perceived as the most astringent one. All three fractions induced significant but comparable loss of salivary lubrication. Yet, when compared to the other fractions, the albumin fraction showed the formation of a thicker and more rigid film on salivary conditioning film-coated sensors as measured using a quartz crystal microbalance with dissipation monitoring (QCM-D). We also present proteomics studies on the precipitates obtained from the mixtures of saliva and pea protein fractions. Protein identification finds a pool of salivary proteins involved in non-specific interactions with all the three pea protein fractions. Yet, 13 pea proteins specific to the albumin fraction were identified as being involved in specific interactions with salivary proteins. Several of these proteins are part of the plant defense mechanisms and are likely to interact with many salivary proteins. This could explain the higher number of salivary proteins found in the precipitate induced by the albumin fraction when compared to the other two. These quantitative results increase the understanding of the complex links between plant protein-salivary protein interactions and astringency
Upper limb amputees can be induced to experience a rubber hand as their own
We describe how upper limb amputees can be made to experience a rubber hand as part of their own body. This was accomplished by applying synchronous touches to the stump, which was out of view, and to the index finger of a rubber hand, placed in full view (26 cm medial to the stump). This elicited an illusion of sensing touch on the artificial hand, rather than on the stump and a feeling of ownership of the rubber hand developed. This effect was supported by quantitative subjective reports in the form of questionnaires, behavioural data in the form of misreaching in a pointing task when asked to localize the position of the touch, and physiological evidence obtained by skin conductance responses when threatening the hand prosthesis. Our findings outline a simple method for transferring tactile sensations from the stump to a prosthetic limb by tricking the brain, thereby making an important contribution to the field of neuroprosthetics where a major goal is to develop artificial limbs that feel like a real parts of the body
c-erbB-4 protein expression in human breast cancer
The Type 1 family of growth factor receptors includes epidermal growth factor receptor (EGFR), c- erb B-2, c- erb B-3 and c- erb B-4. Overexpression of the first two members is associated with poorer prognosis in patients with breast carcinoma. In this study we examined the expression of c- erb B-4 protein using the monoclonal antibody HFR-1. A total of 127 consecutive cases of primary operable invasive breast carcinoma presenting between 1975 and 1977 were studied. All patients were managed by simple mastectomy or conservation surgery with radiotherapy and no adjuvant therapy given. Long-term follow-up was maintained. Routine, formalin-fixed, paraffin-embedded tumour samples were used and sections were stained immunohistochemically using the Duet StreptABC method. Immunoreactivity was classified using a simple semi-quantitative scoring method. Protein expression was generally low but definite positive cytoplasmic, membranous and nuclear reactivity was identified in 58%, 41% and 25% of cases respectively. Expression at all three sites demonstrated significant inverse associations were histological grade. In addition, membrane accentuation correlated inversely with the Nottingham Prognostic Index (NPI), while cytoplasmic reactivity showed a positive association with c- erb B-3 expression. No significant associations were found with disease-free interval or survival. The results of this study demonstrate that higher levels of c- erb B-4 protein expression are associated with a more differentiated histological phenotype in contrast to the other members of the Type 1 family. Larger series with extended follow-up will be required to ascertain definitively the prognostic value of c- erb B-4 expression in breast carcinoma. © 2000 Cancer Research Campaig
Immunization coverage and risk factors for failure to immunize within the Expanded Programme on Immunization in Kenya after introduction of new Haemophilus influenzae type b and hepatitis b virus antigens
Background: Kenya introduced a pentavalent vaccine including the DTP, Haemophilus influenzae type b and hepatitis b virus antigens in Nov 2001 and strengthened immunization services. We estimated immunization coverage before and after introduction, timeliness of vaccination and risk factors for failure to immunize in Kilifi district, Kenya.
Methods: In Nov 2002 we performed WHO cluster-sample surveys of > 200 children scheduled for vaccination before or after introduction of pentavalent vaccine. In Mar 2004 we conducted a simple random sample (SRS) survey of 204 children aged 9 - 23 months. Coverage was estimated by inverse Kaplan-Meier survival analysis of vaccine- card and mothers' recall data and corroborated by reviewing administrative records from national and provincial vaccine stores. The contribution to timely immunization of distance from clinic, seasonal rainfall, mother's age, and family size was estimated by a proportional hazards model.
Results: Immunization coverage for three DTP and pentavalent doses was 100% before and 91% after pentavalent vaccine introduction, respectively. By SRS survey, coverage was 88% for three pentavalent doses. The median age at first, second and third vaccine dose was 8, 13 and 18 weeks. Vials dispatched to Kilifi District during 2001 - 2003 would provide three immunizations for 92% of the birth cohort. Immunization rate ratios were reduced with every kilometre of distance from home to vaccine clinic (HR 0.95, CI 0.91 - 1.00), rainy seasons ( HR 0.73, 95% CI 0.61 - 0.89) and family size, increasing progressively up to 4 children ( HR 0.55, 95% CI 0.41 - 0.73).
Conclusion: Vaccine coverage was high before and after introduction of pentavalent vaccine, but most doses were given late. Coverage is limited by seasonal factors and family siz
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