17 research outputs found

    Identification of the Rheumatoid Arthritis Shared Epitope Binding Site on Calreticulin

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    Background: The rheumatoid arthritis (RA) shared epitope (SE), a major risk factor for severe disease, is a five amino acid motif in the third allelic hypervariable region of the HLA-DRb chain. The molecular mechanisms by which the SE affects susceptibility to – and severity of- RA are unknown. We have recently demonstrated that the SE acts as a ligand that interacts with cell surface calreticulin (CRT) and activates innate immune signaling. In order to better understand the molecular basis of SE-RA association, here we have undertaken to map the SE binding site on CRT. Principal Findings: Surface plasmon resonance (SPR) experiments with domain deletion mutants suggested that the SE binding site is located in the P-domain of CRT. The role of this domain as a SE-binding region was further confirmed by a sulfosuccinimidyl-2-[6-(biotinamido)-2-(p-azido-benzamido) hexanoamido] ethyl-1,3-dithiopropionate (sulfo-SBED) photoactive cross-linking method. In silico analysis of docking interactions between a conformationally intact SE ligand and the CRT P-domain predicted the region within amino acid residues 217–224 as a potential SE binding site. Site-directed mutagenesis demonstrated involvement of residues Glu 217 and Glu 223- and to a lesser extent residue Asp 220- in cell-free SPR-based binding and signal transduction assays. Significance: We have characterized here the molecular basis of a novel ligand-receptor interaction between the SE and CRT. The interaction represents a structurally and functionally well-defined example of cross talk between the adaptive an

    Integrated physical, genetic and genome map of chickpea (Cicer arietinum L.)

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    Physical map of chickpea was developed for the reference chickpea genotype (ICC 4958) using bacterial artificial chromosome (BAC) libraries targeting 71,094 clones (~12× coverage). High information content fingerprinting (HICF) of these clones gave high-quality fingerprinting data for 67,483 clones, and 1,174 contigs comprising 46,112 clones and 3,256 singletons were defined. In brief, 574 Mb genome size was assembled in 1,174 contigs with an average of 0.49 Mb per contig and 3,256 singletons represent 407 Mb genome. The physical map was linked with two genetic maps with the help of 245 BAC-end sequence (BES)-derived simple sequence repeat (SSR) markers. This allowed locating some of the BACs in the vicinity of some important quantitative trait loci (QTLs) for drought tolerance and reistance to Fusarium wilt and Ascochyta blight. In addition, fingerprinted contig (FPC) assembly was also integrated with the draft genome sequence of chickpea. As a result, ~965 BACs including 163 minimum tilling path (MTP) clones could be mapped on eight pseudo-molecules of chickpea forming 491 hypothetical contigs representing 54,013,992 bp (~54 Mb) of the draft genome. Comprehensive analysis of markers in abiotic and biotic stress tolerance QTL regions led to identification of 654, 306 and 23 genes in drought tolerance “QTL-hotspot” region, Ascochyta blight resistance QTL region and Fusarium wilt resistance QTL region, respectively. Integrated physical, genetic and genome map should provide a foundation for cloning and isolation of QTLs/genes for molecular dissection of traits as well as markers for molecular breeding for chickpea improvement

    Reduced hematopoietic reserves in DNA interstrand crosslink repair-deficient Ercc1(−/−) mice

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    The ERCC1-XPF heterodimer is a structure-specific endonuclease involved in both nucleotide excision repair and interstrand crosslink repair. Mice carrying a genetic defect in Ercc1 display symptoms suggestive of a progressive, segmental progeria, indicating that disruption of one or both of these DNA damage repair pathways accelerates aging. In the hematopoietic system, there are defined age-associated changes for which the cause is unknown. To determine if DNA repair is critical to prolonged hematopoietic function, hematopoiesis in Ercc1(−/−) mice was compared to that in young and old wild-type mice. Ercc1(−/−) mice (3-week-old) exhibited multilineage cytopenia and fatty replacement of bone marrow, similar to old wild-type mice. In addition, the proliferative reserves of hematopoietic progenitors and stress erythropoiesis were significantly reduced in Ercc1(−/−) mice compared to age-matched controls. These features were not seen in nucleotide excision repair-deficient Xpa(−/−) mice, but are characteristic of Fanconi anemia, a human cancer syndrome caused by defects in interstrand crosslink repair. These data support the hypothesis that spontaneous interstrand crosslink damage contributes to the functional decline of the hematopoietic system associated with aging

    Cost effectiveness analysis comparing repetitive transcranial magnetic stimulation to antidepressant medications after a first treatment failure for major depressive disorder in newly diagnosed patients – A lifetime analysis

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    Repetitive Transcranial Magnetic Stimulation (rTMS) commonly is used for the treatment of Major Depressive Disorder (MDD) after patients have failed to benefit from trials of multiple antidepressant medications. No analysis to date has examined the cost-effectiveness of rTMS used earlier in the course of treatment and over a patients' lifetime.We used lifetime Markov simulation modeling to compare the direct costs and quality adjusted life years (QALYs) of rTMS and medication therapy in patients with newly diagnosed MDD (ages 20-59) who had failed to benefit from one pharmacotherapy trial. Patients' life expectancies, rates of response and remission, and quality of life outcomes were derived from the literature, and treatment costs were based upon published Medicare reimbursement data. Baseline costs, aggregate per year quality of life assessments (QALYs), Monte Carlo simulation, tornado analysis, assessment of dominance, and one way sensitivity analysis were also performed. The discount rate applied was 3%.Lifetime direct treatment costs, and QALYs identified rTMS as the dominant therapy compared to antidepressant medications (i.e., lower costs with better outcomes) in all age ranges, with costs/improved QALYs ranging from 2,952/0.32(olderpatients)to2,952/0.32 (older patients) to 11,140/0.43 (younger patients). One-way sensitivity analysis demonstrated that the model was most sensitive to the input variables of cost per rTMS session, monthly prescription drug cost, and the number of rTMS sessions per year.rTMS was identified as the dominant therapy compared to antidepressant medication trials over the life of the patient across the lifespan of adults with MDD, given current costs of treatment. These models support the use of rTMS after a single failed antidepressant medication trial versus further attempts at medication treatment in adults with MDD

    Prospective Study of New Participants in a Community-based Mind-body Training Program

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    BACKGROUND: Mind-body practices such as yoga are widely popular, but little is known about how such exercises impact health-related quality of life. OBJECTIVE: To measure changes in health-related quality of life associated with 3 months of mind-body training as practiced in community-based settings. DESIGN: Prospective cohort study. SETTING: Eight centers for practice of mind-body training. PARTICIPANTS: One hundred ninety-four English-speaking adults who had taken no more than 10 classes at the centers prior to enrollment in the study. One hundred seventy-one (88%) returned the 3-month follow-up questionnaire. INTERVENTION: Administration of the SF-36 questionnaire at the start of training and after 3 months. MEASUREMENTS AND MAIN RESULTS: At baseline, new participants in mind-body training reported lower scores than U.S. norms for 7 of 8 domains of the SF-36: mental health, role emotional, social, vitality, general health, body pain, and role physical (P < .002 for all comparisons). After 3 months of training, within-patient change scores improved in all domains (P < .0001), including a change of +15.5 (standard deviation ±21) in the mental health domain. In hierarchical regression analysis, younger age (P= .0003), baseline level of depressive symptoms (P= .01), and reporting a history of hypertension (P= .0054) were independent predictors of greater improvement in the SF-36 mental health score. Five participants (2.9%) reported a musculoskeletal injury. CONCLUSIONS: New participants in a community-based mind-body training program reported poor health-related quality of life at baseline and moderate improvements after 3 months of practice. Randomized trials are needed to determine whether benefits may be generalizable to physician-referred populations
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