Elucidating the cellular immune response to infectious agents is a prerequisite for understanding disease pathogenesis and designing effective vaccines. In the identification of microbial T-cell ...epitopes, the availability of purified or recombinant bacterial proteins has been a chief limiting factor. In chronic infectious diseases such as Lyme disease, immune-mediated damage may add to the effects of direct infection by means of molecular mimicry to tissue autoantigens. Here, we describe a new method to effectively identify both microbial epitopes and candidate autoantigens. The approach combines data acquisition by positional scanning peptide combinatorial libraries and biometric data analysis by generation of scoring matrices. In a patient with chronic neuroborreliosis, we show that this strategy leads to the identification of potentially relevant T-cell targets derived from both Borrelia burgdorferi and the host. We also found that the antigen specificity of a single T-cell clone can be degenerate and yet the clone can preferentially recognize different peptides derived from the same organism, thus demonstrating that flexibility in T-cell recognition does not preclude specificity. This approach has potential applications in the identification of ligands in infectious diseases, tumors and autoimmune diseases.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Summary
Although protists are critical components of marine ecosystems, they are still poorly characterized. Here we analysed the taxonomic diversity of planktonic and benthic protist communities ...collected in six distant
E
uropean coastal sites. Environmental deoxyribonucleic acid (
DNA
) and ribonucleic acid (
RNA
) from three size fractions (pico‐, nano‐ and micro/mesoplankton), as well as from dissolved
DNA
and surface sediments were used as templates for tag pyrosequencing of the V4 region of the 18S ribosomal DNA. Beta‐diversity analyses split the protist community structure into three main clusters: picoplankton‐nanoplankton‐dissolved
DNA
, micro/mesoplankton and sediments. Within each cluster, protist communities from the same site and time clustered together, while communities from the same site but different seasons were unrelated. Both
DNA
and
RNA
‐based surveys provided similar relative abundances for most class‐level taxonomic groups. Yet, particular groups were overrepresented in one of the two templates, such as marine alveolates (
MALV
)‐
I
and
MALV‐II
that were much more abundant in
DNA
surveys. Overall, the groups displaying the highest relative contribution were Dinophyceae, Diatomea, Ciliophora and Acantharia. Also, well represented were Mamiellophyceae, Cryptomonadales, marine alveolates and marine stramenopiles in the picoplankton, and Monadofilosa and basal
F
ungi in sediments. Our extensive and systematic sequencing of geographically separated sites provides the most comprehensive molecular description of coastal marine protist diversity to date.
Purpose: To investigate the association of the rs2301995 haplotype-tagging single nucleotide polymorphism (htSNP) in the elastin gene (ELN) with polypoidal choroidal vasculopathy (PCV) in ...European-American patients.
Methods: Association analysis of allele and genotype frequencies, determined by TaqMan assays, was performed for the rs2301995 haplotype-tagging single nucleotide polymorphism (htSNP) in the ELN locus in fifty-six patients with PCV, 368 patients with advanced age-related macular degeneration (AMD) and 368 age- and ethnically-matched unaffected controls.
Results: The ELN rs2301995 SNP was not statistically significantly associated with the PCV phenotype (P = 0.9). The frequency of the minor allele of the rs2301995 SNP was practically identical in the PCV, AMD and control groups (6.3% vs. 5.4% vs. 7.1%).
Conclusion: The PCV phenotype in European-American patients is not associated with rs2301995 SNP in the ELN locus.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
To measure sustainable improvements in the work environment, a flexible and highly responsive tool is needed that will give important focus to the implementation process. A digital checklist was ...developed in collaboration with key stakeholders to document the implementation of changes in eldercare sector workplaces.
This paper describes the study protocol of a dissemination study that aims to examine when, why, and how the digital checklist is spread to the Danish eldercare sector following a national campaign particularly targeting nursing homes and home care.
This prospective observational study will use quantitative data from Google Analytics describing use of the checklist as documented website engagement, a survey among members in the largest union in the sector, information from a central business register, and monitoring of campaign activities. The evaluation will be guided by the five elements of the RE-AIM framework: reach, effectiveness, adoption, implementation, and maintenance.
The study was approved in June 2016 and began in October 2018. The campaign that is the foundation for the evaluation began in 2017 and ended in 2018. However, the webpage where we collect data is still running. Results are expected in 2020.
This protocol provides a working example of how to evaluate dissemination of a checklist to improve implementation of work environment initiatives in the eldercare sector in Denmark. To our knowledge, implementation in a nationwide Danish work environment has not been previously undertaken. Given that the checklist is sector-specific for work environment initiatives and developed through systematic collaboration between research and practice, it is likely to have high utility and impact; however, the proposed evaluation will determine this. This study will advance dissemination research and, in particular, the evaluation of the impact of these types of studies. Finally, this study advances the field through digital tools that can be used for evaluation of dissemination efforts (eg, Google Analytics associated with website) in the context of a rigorous research design activity.
DERR1-10.2196/16039.
Time-dependent density functional theory (TD-DFT) is used to examine the effect of stacking in a model semiconducting polymer hetrojunction system consisting of two co-facially stacked oligomers. We ...find that the excited electronic states are highly sensitive to the alignment of the monomer units of the two chains. In the system we examined, the exchange energy is nearly identical to both the and band off-set at the heterojunction and to the exciton binding energy. Our results indicate that the triplet excitonic states are nearly degenerate with the singlet exciplex states opening the possibility for the interconversion of singlet and triplet electronic states at the heterojunction interface via spin–orbit coupling localized on the heteroatoms. Using Russell–Saunders theory, we estimate this interconversion rate to be approximately 700–800
ps, roughly a 5–10-fold increase compared to isolated organic polymer chains.
Factors affecting the progression of renal disease in autosomal-dominant polycystic kidney disease. Autosomal-dominant polycystic kidney disease results in renal failure at a varying age from ...childhood to old age. We postulated that factors other than the culprit gene alone contribute to the course of progression of the renal failure. We studied 580 subjects with autosomal-dominant polycystic kidney disease and 194 unaffected family members. We calculated survival curves to end-stage renal failure or death and developed a linear model for testing the effects of single or multiple variables on the progression of renal failure as estimated from the reciprocal of serum creatinine. Fifty-two subjects died and 94 reached end-stage renal failure during the period of observation, yielding functional survivals of 71% at age 50 years, 53% at 58 years and 23% at 70 years. The following variables were independently associated with worse mean renal function at a given age (P value less than 0.01): the PKD1 gene, younger age at diagnosis, male gender, hypertension, increased left ventricular mass, hepatic cysts in women, three or more pregnancies, gross hematuria, urinary tract infections in men and renal size expressed as renal volume. The following were not associated significantly with the course of renal function: gender of affected parent, mitral valve prolapse, intracranial aneurysms, any pregnancy, hepatic cysts in men and urinary tract infections in women. The identification of unalterable maleficent factors such as the PKD1 gene and male gender permit more informed counseling while the identification of alterable factors such as hypertension, number of pregnancies and recurrent urinary tract infections provides the clinician with the opportunity to modify these factors and improve the management of patients with autosomal-dominant polycystic kidney disease.
Abstract only
G‐protein‐coupled receptors (GPCRs) represent one of the largest and most important classes of membrane proteins for drug discovery. However, due to their inherent flexibility and ...instability outside of the membrane, they are challenging targets for structural and biophysical studies. Here we demonstrate how these challenges have been overcome through protein engineering, by identifying a minimal number of thermostabilising mutations that can lock a receptor in a single conformation and enhance its survival in a detergent environment. This has been applied to GPCRs from families A, B and C, with peptide or small molecule ligands, and to orphan receptors with no known ligand. The resulting stabilised receptors (StaRs) are more amenable to purification, crystallisation and biophysical analysis of ligand binding.
Using this approach, StaRs were generated for Orexin 1 and Orexin 2, two peptide GPCRs involved in regulating the sleep‐wake cycle. The StaRs show decreased agonist signalling, whilst maintaining antagonist binding, consistent with a shift to the antagonist conformation. Structural determination, together with biophysical mapping and fragment screening using surface plasmon resonance (SPR), has led to the rapid identification of highly optimised dual Orexin receptor antagonists (DORAs) with very high affinity, good pharmacokinetics and excellent in vivo activity in models of insomnia.
Childhood osteogenic sarcoma (OS) is a rare bone cancer occurring primarily in adolescents. The North American pediatric cooperative groups have performed a series of clinical treatment trials in ...this disease over the past several decades, and biology studies of tumor tissue have been an important study component. A meeting was held in Bethesda, Maryland on November 29-30, 2001, sponsored by the NIH Office of Rare Diseases, the Children's Oncology Group, and the National Cancer Institute-Cancer Therapy Evaluation Program with the general objectives: (a) to review the current state of knowledge regarding OS biology; (b) to identify, prioritize, and support the development of biology studies of potential clinical relevance in OS; and (c) to discuss the available tissue resources and the appropriate methods for analysis of OS samples for the conduct of biology studies. This report summarizes the information presented and discussed by the meeting participants.
Jones, I. M., Galick, H., Kato, P., Langlois, R. G., Mendelsohn, M. L., Murphy, G. A., Pleshanov, P., Ramsey, M. J., Thomas, C. B., Tucker, J. D., Tureva, L., Vorobstova, I. and Nelson, D. O. Three ...Somatic Genetic Biomarkers and Covariates in Radiation-Exposed Russian Cleanup Workers of the Chernobyl Nuclear Reactor 6–13 Years after Exposure. Radiat. Res. 158, 424–442 (2002). Three somatic mutation assays were evaluated in men exposed to low-dose, whole-body, ionizing radiation. Blood samples were obtained between 1992 and 1999 from 625 Russian Chernobyl cleanup workers and 182 Russian controls. The assays were chromosome translocations in lymphocytes detected by FISH, hypoxanthine phosphoribosyltransferase (HPRT) mutant frequency in lymphocytes by cloning, and flow cytometic assay for glycophorin A (GPA) variant frequency of both deletion (N/Ø) and recombination (N/N) events detected in erythrocytes. Over 30 exposure and lifestyle covariates were available from questionnaires. Among the covariates evaluated, some increased (e.g. age, smoking) and others decreased (e.g. date of sample) biomarker responses at a magnitude comparable to Chernobyl exposure. When adjusted for covariates, exposure at Chernobyl was a statistically significant factor for translocation frequency (increase of 30%, 95% CI of 10%–53%, P = 0.002) and HPRT mutant frequency (increase of 41%, 95% CI of 19%–66%, P < 0.001), but not for either GPA assay. The estimated average dose for the cleanup workers based on the average increase in translocations was 9.5 cGy. Translocation analysis is the preferred biomarker for low-dose radiation dosimetry given its sensitivity, relatively few covariates, and dose–response data. Based on this estimated dose, the risk of exposure-related cancer is expected to be low.
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