450 research outputs found
Primer: making sense of T-cell memory.
No full textProtective memory is a key property of the immune system. Pathogen-associated molecular patterns of invading organisms deliver signals to pattern-recognition receptors that activate the innate immune system. Ligation of the T-cell receptor by peptides bound to MHC antigens and presented by dendritic cells, together with signals produced by the activated innate immune system, initiate T-cell responses. The nature of the T-cell response, consisting of phases of clonal expansion and contraction, and differentiation to effector and memory cells, however, is determined both by the properties of the antigen and the co-stimuli produced by the innate immune system. Short-lived effector and longer-lived memory T cells are generated during primary responses; after the death of most of the effectors, memory cells remain. Memory cells are heterogeneous in phenotype and function; subsets include the relatively quiescent central and more activated effector memory cells, as well as cells able to promote inflammation, help antibody production or regulate other immune responses. Understanding the properties of memory cells will help in the rational design of vaccines for 'difficult' organisms or cancer, as well as immunotherapies for autoimmune diseases
Generation of T-cell memory.
No full textRecent studies of T-cell memory have suggested that the persistent presence of the priming antigen is not necessary for maintenance of CD8 memory. Factors contributing to the development of memory from activated T cells remain ill defined but accumulating data suggest that cytokines play a key role in this process. There has also been recent progress in understanding turnover of naive and memory cells in the mouse
Approaches to the study of the geometry and mechanisms of nucleophilic substitution at oxygen, sulfur (II), and chlorine: Applications of the endocyclic restriction test
No full textRestriction data tranferred 2014-07-01T11:29:25-05:00
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Reason: ETDs are only available to UIUC Users without author permissionETDs are only available to UIUC Users without author permissionU of I OnlyApproaches toward studying the geometry of nucleophilic substitution at oxygen, sulfur (II), and chlorine have been investigated. The endocyclic restriction test has been applied with both double-labeling studies and \sp1H NMR Spin Saturation Transfer techniques utilized as methods of analysis.An oxygen-18 labeling experiment has been used to address the geometrical limitations and requirements in the transition state for olefin epoxidation by sulfonyl oxaziridines. Mass spectral analysis of the distribution of labels in the double-labeling experiment for the conversion of 106 to 107 was consistent with an intramolecular oxygen atom transfer. This indicates that the oxygen atom transfer does not require the olefin to approach the oxaziridine at a large angle relative to the O-N bond in the transition state.One dimensional \sp1H NMR spin saturation transfer techniques have been utilized to study the rate of sulfenyl group transfer in 134-{\bf d\sb4}. The apparent lack of concentration effects in Cl\sb2CDCDCl\sb2 suggest that the transfer may have proceeded intramolecularly through a six-membered endocyclic transition state. However, the disappearance of the diamine 133 in an intermolecular control crossover experiment with the disulfenamide 135 without any effect on 135 raises doubt concerning the interpretation of the results from the spin saturation transfer experiments. An approach which would test the geometrical requirements for scrambling of the sulfenyl moiety between nitrogen atoms tethered together without the necessity of using spin saturation transfer analysis has been initiated and described.Double-labeling analysis incorporating \sp{37}Cl has been utilized to study the geometry of substitution at chlorine. Crossover experiments between 144 and 144-{\bf d}\sb{\bf 3},\sp{\bf 37}{\bf Cl} indicated that either the transfer occurred intermolecularly to give the substituted chloro-aromatics 145 or that chlorine scrambling of either the starting materials or products had occurred. Control experiments ruled out the possibility of scrambling occurring in the products. However, crossover experiments between 147 and 147-{\bf d}\sb{\bf 3},\sp{\bf 37}{\bf Cl} indicate that scrambling between the starting materials may have occurred. Thus, no conclusions were drawn from this work.Made available in DSpace on 2011-05-07T14:00:55Z (GMT). No. of bitstreams: 2
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CD45 regulates apoptosis in peripheral T lymphocytes
No full textProgrammed cell death (apoptosis) is a key mechanism for regulating lymphocyte numbers. Murine lymph node lymphocytes cultured in vitro without added stimuli show significant levels of apoptosis over 24 h, detectable by staining with Annexin V. CD4 and CD8 T lymphocytes from transgenic (Tg) mice expressing single CD45RABC or CD45RO isoforms show increased apoptosis and the extent of apoptosis is inversely correlated with the level of CD45 expression. CD45 Tg cells exhibit phosphatidyl serine translocation and DNA oligonucleosome formation, and can be partially rescued from apoptosis by culture in caspase inhibitors or common gamma-chain-binding cytokines. We conclude that CD45 is an important regulator of spontaneous apoptosis in T lymphocytes and this mechanism may contribute to the disease associations reported for individuals expressing CD45 variant alleles
Three options for citation tracking: Google Scholar, Scopus and Web of Science
No full textBackground:
Researchers turn to citation tracking to find the most influential articles for a particular topic, and to see how often their own published papers are cited. For years researchers looking for this type of information had only one resource to consult: the Web of Science. In 2004, two competitors emerged – Scopus and Google Scholar. The research reported here uses citation analysis in an observational study examining these three databases; comparing citation counts for articles from two disciplines (oncology and condensed matter physics) and two years (1993 and 2003).
Methods:
11 journal titles with varying impact factors were selected from each discipline (oncology and condensed matter physics) using the Journal Citation Reports (JCR). All articles published in the selected titles were retrieved for both years, and a stratified random sample of articles was chosen, resulting in four sets of articles. During the week of November 7-12, 2005 we extracted the citation counts for each research article from the three sources. The actual citing references for a subset of the articles published in 2003 were also gathered from each of the three sources.
Results:
For oncology 1993, Web of Science returned the highest average number of citations, 45.3. Scopus returned the highest average number of citations (8.9) for oncology 2003. Web of Science returned the highest number of citations for condensed matter physics 1993 and 2003 (22.5 and 3.9 respectively). The data showed a significant difference in the mean citation rates between all pairs of resources except between Google Scholar and Scopus for condensed matter physics 2003. For articles published in 2003, Google Scholar returned the largest amount of unique citing material for oncology and Web of Science returned the most for condensed matter physics.
Conclusions:
This study did not identify any one of these three resources as the answer to all citation tracking needs. Scopus showed strength in providing citing literature for 2003 oncology articles, while Web of Science produced more citing material for 2003 and 1993 condensed matter physics, and 1993 oncology articles. Unique material was returned by all three tools. Our data indicate that the question of which tool provides the most complete set of citing literature may depend on the subject and publication year of a given article
Effects of Enhanced Milieu Training with Phonological Emphasis (EMT+PE) on Child with Cleft Lip +/- Palate Speech & Language Outcomes – A Pilot Telepractice Parent Training Study
No full textabstract: Purpose: The purpose of this study was to determine the effectiveness of parent training in Enhanced Milieu Teaching with Phonological Emphasis (EMT+PE) using telepractice on the speech and language outcomes of children with cleft lip and/or palate (CL/P).
Method: Three parent-child dyads participated in the study. All child participants had nonsyndromic CL/P and ranged in age from 21 to 27months. Participants received three weekly telepractice intervention sessions, along with a total of three in-person parent training sessions. Intervention and training were conducted by an SLP and trained graduate student.
Results: All speech measures indicated a gain in essential speech skills for all three children when comparing pre-intervention to post-intervention assessment results. Positive improvement was seen across multiple language measures for all participants.
Conclusion: A parent implemented EMT+PE intervention program using telepractice is an effective way to increase child speech and language outcomes for children with CL/P. Speech and language targets should be combined and delivered simultaneously in intervention
"Leishmania infantum" : molecular analysis for identification of potential virulence factors and genes of diagnostic use
No full textLeishmania infantum is the causative agents of zoonotic visceral leishmaniasis, a fatal disease if left untreated. In Southern Europe, the number of HIV/Leishmania infantum co-infections is increasing and becomes an emerging concern for the public health. Dogs represent the main reservoir of this parasite. In order to control canine leishmaniasis, an early diagnosis system is needed because dogs are capable to transmit the parasite, before showing any symptoms of the disease. Here fore, cDNA expression libraries were screened with sera of infected dogs. We selected several antigens reacting with the sera. These were different histones, ribosomal and mitochondrial proteins. Four of them were subcloned into expression plasmids, and recombinantly expressed in E. coli. The purified proteins were sent to a collaborating laboratory for further examination. Although several diagnostic polymerase chain reactions (PCRs) for Leishmania species causing human leishmaniasis are published, none of them is able to detect all different species and distinguish among them at the same time. Therefore, a diagnostic PCR was developed using the mini-exon gene (encoding the spliced leader) as template. A restriction fragment length polymorphism (RFLP) scheme was elaborated in order to identify different Leishmania species causing human leishmaniasis. The PCR and RFLP scheme is now in routine use at the STI. In order to identify potential virulence factors, vaccine candidates and drug targets of Leishmania infantum, two cDNA subtractions were performed: (1) A none-infective L. infantum strain was subtracted from a highly infective strain. Several genes which were higher or exclusively expressed in the infective strain were identified. However, association with virulence could not be shown, since the two strains differed not only in virulence but also in growth rate. (2) Non-infective early promastigote stages were subtracted from late promastigote stages (metacyclic transmission stage) of the same strain. Several genes showing differential expression were selected including genes encoding nutrient transporters, cytochrome b5 and unknown proteins. One of them was the previously described metacyclic specific gene MAT-1. Three of the genes were recombinantly expressed in E. coli in order to perform immunization and preliminary localization studies
Ion Exchange as Pretreatment of Municipal Wastewater Effluent for Reverse Osmosis Desalination: Assessment of treatment performance and prediction of fouling potential on downstream reverse osmosis
No full textBiofouling and scaling are ongoing challenges for reverse osmosis (RO) membranes application in wastewater reclamation. Adequate RO feed pretreatment is necessary for biofouling and scaling control. The objective of this thesis was evaluated the effectiveness of ion exchange treatment with weak acid cation (WAC) and strong base anion (SBA) resins columns, in series, after ultrafiltration (UF) treatment for the pretreatment of municipal wastewater treatment plant effluent in order to be used for RO desalination. Specifically, the performance of two SBA resins, the Amberlite SCAV4 Cl (SCAV4) and the Amberlite IRA458 Cl (IRA458) was assessed at three regeneration levels (120, 100 and 80 g NaCl/Lr). The effect of the different regeneration levels on anions removal (sulfate, phosphate and nitrate), total organic carbon (TOC) removal and the operational exchange capacity was researched. Moreover, the subsequent effect on RO biofouling and scaling potential was investigated based on the product water quality of the two SBA resins with bio-growth potential tests and software tests (WAVE design, PHREEQC 3 and Avista Ci), respectively. Phosphate and sulfate removal was above 97% for both resins at all regeneration levels. TOC removal of about 70% was achieved in all cases. It was also observed that sulfate, phosphate and TOC removal remained the same up to the point where product nitrate concentration reached its feed concentration. The removal of nitrate was influenced by the regeneration level. For both SBA resins, a lower regeneration level caused a higher nitrate baseline leakage in product water, hence to a lower removal. The macroporous SCAV4 found to have higher selectivity towards nitrate compared to the gel IRA458. Nevertheless, the anion selectivity order for both SCAV4 and IRA458 was HCO3- < NO3- < HPO42- < SO42-. A minor increase in the operational exchange capacity for both SBA resins was observed at higher regeneration levels. Overall, the influence of the different regeneration levels was found to be limited towards the product water quality and the operational exchange capacity. Also, both SBA resins resulted to similar product water quality. The operational exchange capacity of IRA458 at each regeneration level was higher than that of SCAV4, due to the former’s greater total exchange capacity. The RO feed water quality produced without ion exchange pretreatment (only UF) supported bacterial growth up to 54 ± 1.5 × 106 cells/mL. The RO feed water qualities produced with ion exchange pretreatment in the cases of SCAV4 and IRA458 supported bacterial growth up to 3.4 ± 0.3 × 106 cells/mL and to 1.25 ± 0.2 × 106 cells/mL, respectively. The resulted reduction in the bacterial growth potential was above 90% after ion exchange treatment with either one of the tested SBA resins. The growth-limiting nutrient for the RO feed water qualities produced by either SBA resin was phosphorus. The bacterial growth supported by the two RO feed water qualities produced with ion exchange pretreatment after extra phosphorus addition was 80% lower than that supported by the RO feed water quality produced without ion exchange. This difference suggests that both SBA resins removed a considerable fraction of assimilable organic carbon (AOC). It was concluded that ion exchange pretreatment with either one of the tested SBA resins resulted in nutrients removal (P and C) in the RO feed that lowers the biofouling potential compared to RO feed pretreatment with only UF. The software results suggest lower scaling potential for several scalant types in the RO feed after ion exchange treatment with either one of the tested SBA resins. Among them was calcium phosphate, which was found to have high scaling potential in RO feed without ion exchange treatment (only UF) either with or without anti-scalant dosing. However, the scaling potential of some silica and iron based minerals was high, thus anti-scalant dosing might be required.Water Managemen
Two eighteenth-century English adaptations of the Celestina : Celestina: or the Spanish bawd : a tragi-comedy; and the Bawd of Madrid.
No full textPhDThe introductory chapter discusses previous studies of Celestina
imitations and adaptations, and the position of early Celestinesque
works in Spanish literature. I then move further afield to investigate
the diffusion of the Celestina in the rest of Europe, especially in
England. Chapter II comments on the general influence of Spain on
English literature with particular reference to the two eighteenth-century
adaptations of the Celestina. Chapter III suggests some
implications of the simultaneous appearance of these two adaptations.
Chapters IV-VI are devoted to a closer examination of the dramatic
adaptation, A Tragi-Comedy; an investigation into its sources, and
the manner in which it remodels its original for the stages culminates
in a discussion of the adapters' identity. Chapters VII-IX deal with
The Bawd of Madrid; a biographical sketch of its author, Captain
Stevens, is followed by a discussion of which version of the Celestina
he used and of the sources for the description of Madrid in his first
chapter. Chapter IX looks at the way he reworks the Spanish Tragi-comedia
into a narrative account. I bring together in Chapter X
elements from both adaptations for purposes of comparison. The final
chapter shows the similarities between the fictional world of the
Celestina and the environment of early eighteenth-century London, and
I suggest why these English adaptations may have been particularly
apposite at this time
Seronegative spondyloarthropathies : a review : part II: genetics and pathogenesis
No full textIn none of the spondyloarthropathies is the pathogenesis well understood. Much of the investigation into the aetio-pathogenesis of these diseases has focused on the association with HLA-B27 and the known triggering potential of certain infectious agents. In this article the author describes that the HLA linked genes which is subdivided into three groups, class I, class II and class III, which are structurally and functionally distinct from each other.peer-reviewe
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