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101.
EM Yoshida LA Mandl SR Erb AB Buckley CH Scudamore NA Buskard 《Canadian Metallurgical Quarterly》1997,24(4):274-275
The loss of immunotolerance has been implicated in the pathogenesis of both primary biliary cirrhosis (PBC) and idiopathic, immune-mediated thrombocytopenic purpura (ITP). An association between these two autoimmune diseases has been well described. We describe a 41-year-old woman in whom ITP developed 457 days after liver transplantation for PBC while receiving immunosuppressive medications sufficient to maintain allograft function. Our case report, the first to describe post-transplant ITP in association with PBC, demonstrates the persistence of the underlying immune dysregulation of PBC after transplantation. The practice of decreasing the dosage of immunosuppressive medication to maintenance levels after transplantation may unmask the effects of this defect in immunotolerance. 相似文献
102.
LA Bentolila GE Wu F Nourrit M Fanton d'Andon F Rougeon N Doyen 《Canadian Metallurgical Quarterly》1997,158(2):715-723
N region diversity in Ag receptors is a developmentally regulated process in B and T cells that correlates with the differential expression of terminal deoxynucleotidyl transferase (TdT). Absent in fetal and newborn mice, TdT expression is restricted to early T and pro-B cells in adults. To extend the TdT expression pattern throughout B cell ontogenesis, we generated transgenic mice carrying a TdT cDNA under the regulatory elements of the N-myc gene and the IgH enhancer. High expression was observed in secondary lymphoid organs consistent with TdT activity beyond the pre-B cell stage. This suggests that TdT transgene expression is not down-regulated as is the endogenous gene. Unlike normal mice, extensive N region diversity was found in rearranged lambda light chain genes of adult transgenic animals. Therefore, expression of TdT appears sufficient for N region diversity to occur at any Ig locus. More importantly, expression of the transgene takes place during fetal development. As a consequence, the potential fetal B cell repertoire is modified as both rearranged heavy and light chain genes now show N region additions. Constitutive expression of TdT throughout B cell differentiation does not therefore appear deleterious and suggests that TdT is recruited only to participate in the V(D)J recombination process. 相似文献
103.
Dentists are often called upon to perform painful procedures on children. This may present a management problem for the practitioner who is unfamiliar with accepted behavioural management techniques or prescribing analgesics for paediatric patients. This article will review techniques that may be used to guide a child patient's behaviour through painful procedures as well as addressing the need for post-operative analgesics in the paediatric population. 相似文献
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M González LA Bagatolli I Echabe JL Arrondo CE Argara?a CR Cantor GD Fidelio 《Canadian Metallurgical Quarterly》1997,272(17):11288-11294
The effect of biotin binding on streptavidin (STV) structure and stability was studied using differential scanning calorimetry, Fourier transform infrared spectroscopy (FT-IR), and fluorescence spectroscopy. Biotin increases the midpoint temperature Tm, of thermally induced denaturation of STV from 75 degrees C in unliganded protein to 112 degrees C at full ligand saturation. The cooperativity of thermally induced unfolding of STV changes substantially in presence of biotin. Unliganded STV monomer has at least one domain that unfolds independently. The dimer bound to biotin undergoes a single coupled denaturation process. Simulations of thermograms of STV denaturation that take into account only the thermodynamic effects of the ligand with a Ka approximately 10(15) reproduce the behavior observed, but the estimated values of Tm are 15-20 degrees C lower than those experimentally determined. This increased stability is attributed to an enhanced cooperativity of the thermal unfolding of STV. The increment in the cooperativity is as consequence of a stronger intersubunit association and an increased structural order upon binding. FT-IR and fluorescence spectroscopy data reveal that unordered structure found in unliganded STV disappears under fully saturating conditions. The data provide a rationale for previous suggestions that biotin binding induces an increase in protein tightness (structural cooperativity) leading, in turn, to a higher thermostability. 相似文献
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Kieran Jordan Marion Dalmasso Juergen Zentek Anneluise Mader Geert Bruggeman John Wallace Dario De Medici Alfonsina Fiore Estella Prukner‐Radovcic Maja Lukac Lars Axelsson Askild Holck Hanne Ingmer Mindaugas Malakauskas 《Journal of the science of food and agriculture》2014,94(15):3079-3089
Foodborne illness continues as a considerable threat to public health. Despite improved hygiene management systems and increased regulation, pathogenic bacteria still contaminate food, causing sporadic cases of illness and disease outbreaks worldwide. For many centuries, microbial antagonism has been used in food processing to improve food safety. An understanding of the mode of action of this microbial antagonism has been gained in recent years and potential applications in food and feed safety are now being explored. This review focuses on the potential opportunities presented, and the limitations, of using microbial antagonism as a biocontrol mechanism to reduce contamination along the food chain; including animal feed as its first link. © 2014 Society of Chemical Industry 相似文献
109.
Cover Picture: Tetrahydroisoquinolinone‐Based Steroidomimetic and Chimeric Microtubule Disruptors (ChemMedChem 1/2014) 下载免费PDF全文
110.
The paper focuses on a cooperative environment in wireless ad hoc networks, where mobile nodes share information in a peer-to-peer fashion. Nodes follow a pure peer-to-peer approach (i.e., without the intervention of servers), thus requiring an efficient query/response propagation algorithm to prevent network congestion. The main contribution of the paper is the proposal of a novel solution, called Eureka, that identifies the regions of the network where the required information is more likely to be stored and steers the queries toward those regions. To discriminate among regions, the concept of information density is introduced, along with a procedure that allows nodes its estimation. Eureka does not require the use of satellite positioning systems, and proves to be very effective in both vehicular and pedestrian environments. 相似文献