179 research outputs found

    DIAGNOSTIC VALUE OF SEROLOGICAL MARKERS OF RHEUMATOID ARTHRITIS

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    Rheumatoid arthritis (RA) is a classic autoimmune disease associated with the production of wide range of autoantibodies, and their detection has diagnostic and prognostic implication. The objective of this study was to estimate the diagnostic value of antibodies against modified citrullinated vimentin (AMCV) and nuclear antigen RA33 of the IgA rheumatoid factor (RF) versus the value of routinely used profile of autoantibodies in diagnostic work-up of RA. Material and methods. 253 patients with RA prehistory of varying duration were included into the study group. The control group was comprised of 92 patients, including patients with seronegative spondyloarthropathies and diffuse connective tissue diseases, as well as sex and age matched healthy controls. Serum levels of IgM and IgA RF, antibodies against cyclic citrullinated peptide (ACCP), ACMV, anti-keratin antibodies (AKA), antibodies against RA33 antigen (ARA33) and antinuclear factor (ANF) were measured in all patients and controls. Results and discussion. Diagnostic sensitivity of AMCV equaled 78%, ACCP — 77%, IgM RF — 71%, IgA RF — 43%, AKA — 43%, ARA33 — 31% and ANF — 31%. All anti-citrullinic antibodies (AKA, ACCP, ACMV) were significantly more commonly associated with IgM RF. Among RF and ACCP seronegative patients ACMV were found in 24% cases with 20 IU/Ml detection threshold, and in 21% — with 30 IU/Ml, allowing to increase diagnostic specificity of the test up to 91% with the increment of diagnostic threshold. Incidence of ARA33 was not significantly different among the RF and ACCP positive or negative subgroups, thus making ARA33 an independent RA marker. Specificity of this marker was 87,9%, thus making it inferior to RF and ACCP by a composite of diagnostic characteristics. Conclusions. Integrated measurement of ACMV and ARA33 is a rational approach at the second stage of serologic testing work-up in suspected cases of RA onset, when initial RF and ACCP tests were negative

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

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    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    Timing the multiple cell death pathways initiated by Rose Bengal acetate photodynamic therapy

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    Rose Bengal acetate photodynamic therapy (RBAc–PDT) induced multiple cell death pathways in HeLa cells through ROS and ER stress. Indeed, apoptosis was the first preferred mechanism of death, and it was triggered by at least four different pathways, whose independent temporal activation ensures cell killing when one or several of the pathways are inactivated. Apoptosis occurred as early as 1 h after PDT through activation of intrinsic pathways, followed by activation of extrinsic, caspase-12-dependent and caspase-independent pathways, and by autophagy. The onset of the different apoptotic pathways and autophagy, that in our system had a pro-death role, was timed by determining the levels of caspases 9, 8, 3 and 12; Bcl-2 family; Hsp70; LC3B; GRP78 and phospho-eIF2α proteins. Interestingly, inhibition of one pathway, that is, caspase-9 (Z-LEHD-FMK), caspase-8 (Z-IETD-FMK), pan-caspases (Z-VAD-FMK), autophagy (3-MA) and necrosis (Nec-1), did not impair the activation of the others, suggesting that the independent onset of the different apoptotic pathways and autophagy did not occur in a subordinated manner. Altogether, our data indicate RBAc as a powerful photosensitiser that induces a prolonged cytotoxicity and time-related cell death onset by signals originating from or converging on almost all intracellular organelles. The fact that cancer cells can die through different mechanisms is a relevant clue in the choice and design of anticancer PDT

    Photochemical internalisation of chemotherapy potentiates killing of multidrug-resistant breast and bladder cancer cells

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    Multidrug resistance (MDR) is the major confounding factor in adjuvant solid tumour chemotherapy. Increasing intracellular amounts of chemotherapeutics to circumvent MDR may be achieved by a novel delivery method, photochemical internalisation (PCI). PCI consists of the co-administration of drug and photosensitiser; upon light activation the latter induces intracellular release of organelle-bound drug. We investigated whether co-administration of hypericin (photosensitiser) with mitoxantrone (MTZ, chemotherapeutic) plus illumination potentiates cytotoxicity in MDR cancer cells. We mapped the extent of intracellular co-localisation of drug/photosensitiser. We determined whether PCI altered drug-excreting efflux pump P-glycoprotein (Pgp) expression or function in MDR cells. Bladder and breast cancer cells and their Pgp-overexpressing MDR subclones (MGHU1, MGHU1/R, MCF-7, MCF-7/R) were given hypericin/MTZ combinations, with/without blue-light illumination. Pilot experiments determined appropriate sublethal doses for each. Viability was determined by the 3-[4,5-dimethylthiazolyl]-2,5-diphenyltetrazolium bromide assay. Intracellular localisation was mapped by confocal microscopy. Pgp expression was detected by immunofluorescence and Pgp function investigated by Rhodamine123 efflux on confocal microscopy. MTZ alone (0.1–0.2 μg ml−1) killed up to 89% of drug-sensitive cells; MDR cells exhibited less cytotoxicity (6–28%). Hypericin (0.1–0.2 μM) effects were similar for all cells; light illumination caused none or minimal toxicity. In combination, MTZ /hypericin plus illumination, potentiated MDR cell killing, vs hypericin or MTZ alone. (MGHU1/R: 38.65 and 36.63% increase, P<0.05; MCF-7/R: 80.2 and 46.1% increase, P<0.001). Illumination of combined MTZ/hypericin increased killing by 28.15% (P<0.05 MGHU1/R) compared to dark controls. Intracytoplasmic vesicular co-localisation of MTZ/hypericin was evident before illumination and at serial times post-illumination. MTZ was always found in sensitive cell nuclei, but not in dark resistant cell nuclei. In illuminated resistant cells there was some mobilisation of MTZ into the nucleus. Pgp expression remained unchanged, regardless of drug exposure. Pgp efflux was blocked by the Pgp inhibitor verapamil (positive control) but not impeded by hypericin. The increased killing of MDR cancer cells demonstrated is consistent with PCI. PCI is a promising technique for enhancing treatment efficacy

    A Prospective Study of Return to Work Across Health Conditions: Perceived Work Attitude, Self-efficacy and Perceived Social Support

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    Background The aim of the present study was to conduct subgroup-analyses in a prospective cohort of workers on long-term sickness absence to investigate whether associations between perceived work attitude, self-efficacy and perceived social support and time to RTW differ across different health conditions. Methods The study was based on a sample of 926 workers on sickness absence (6–12 weeks). The participants filled out a baseline questionnaire and were subsequently followed until the tenth month after listing sick. Perceived work attitude was measured with a Dutch language version of the Work Involvement Scale. Perceived social support was measured with a self-constructed standardized scale reflecting a person’s perception of social support regarding RTW. Self-efficacy was measured with the standardised Dutch version of the General self-efficacy scale, assessing the subjects’ expectations of their general capacities. The sample was divided into three subgroups: musculoskeletal health conditions, other physical health conditions and mental health conditions. Anova analyses and Cox proportional hazards regression analyses were used to identify differences in association between the three factors and the time to RTW between different subgroups. Results The associations between the perceived work attitude, self-efficacy and perceived social support and the time to RTW vary across different health condition subgroups, not only with regard to the strength of the association but also for the type of factor. In the multivariate model, hazard ratios (HRs) of 1.33 (95% CI 1.01–1.75) in the musculoskeletal subgroup, and 1.26 (95% CI 0.89–1.78) in the other physical subgroup were found in perceived work attitude. With regard to perceived social support HRs of 1.39 (95% CI 1.12–1.99) respectively 1.51 (1.05–2.17) in the same subgroups were found. Only self-efficacy remained in the multivariate model in all subgroups with HRs of 1.49 (95% CI 1.12–1.99) in the musculoskeletal subgroup, 1.53 (95% CI 1.07–2.18) in the other physical subgroup and 1.60 (1.07–2.40) in the mental subgroup. Conclusions The results of this study show that perceived work attitude, self-efficacy and perceived social support are relevant predictors with regard to the time to RTW in all types of health conditions, but that important differences are observed in type of factor and strengths of the relationships between physical and mental health conditions

    Photodynamic therapy of DNA mismatch repair-deficient and -proficient tumour cells

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    Loss of DNA mismatch repair is a common finding in hereditary nonpolyposis colon cancer as well as in many types of sporadic human tumours. DNA mismatch repair-deficient cells have been reported to be resistant to many chemotherapeutic agents and to radiotherapy, and to have the potential of rapidly acquiring additional mutations leading to tumour progression. Photodynamic therapy is a new treatment modality using light to activate a photosensitiser that preferentially localises in tumour cells. An oxygen dependent photochemical reaction ensues, resulting in selective tumour necrosis. The effect of loss of DNA mismatch repair activity on the sensitivity to photodynamic therapy was tested using pairs of cell lines proficient or deficient in mismatch repair due to loss of either MLH1 or MSH2 protein function. Cells were incubated with the photosensitiser 5,10,15,20-meta-tetra(hydroxyphenyl)chlorin and exposed to laser light at 652 nm with various optical doses ranging from 0–1 J cm−2. Cell survival was assessed using the clonogenic assay. Loss of MLH1 or MSH2 function was not associated with resistance to photodynamic therapy. MCF-7 cells repeatedly treated with photodynamic therapy expressed parental levels of MLH1, MSH2, MSH6, and PMS2. DNA mismatch repair-deficient and -proficient cells showed similar subcellular distributions of meta-tetra(hydroxyphenyl)chlorin as analysed by laser scanning and fluorescence microscopy. Therefore, repeated exposure of tumour cells to photodynamic therapy does not seem to result in loss of DNA mismatch repair, and loss of mismatch repair, in turn, does not seem to contribute to resistance to photodynamic therapy. Our results suggest recommending photodynamic therapy as a strategy for circumventing resistance due to loss of DNA mismatch repair

    Intracellular Targeting Specificity of Novel Phthalocyanines Assessed in a Host-Parasite Model for Developing Potential Photodynamic Medicine

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    Photodynamic therapy, unlikely to elicit drug-resistance, deserves attention as a strategy to counter this outstanding problem common to the chemotherapy of all diseases. Previously, we have broadened the applicability of this modality to photodynamic vaccination by exploiting the unusual properties of the trypanosomatid protozoa, Leishmania, i.e., their innate ability of homing to the phagolysosomes of the antigen-presenting cells and their selective photolysis therein, using transgenic mutants endogenously inducible for porphyrin accumulation. Here, we extended the utility of this host-parasite model for in vitro photodynamic therapy and vaccination by exploring exogenously supplied photosensitizers. Seventeen novel phthalocyanines (Pcs) were screened in vitro for their photolytic activity against cultured Leishmania. Pcs rendered cationic and soluble (csPcs) for cellular uptake were phototoxic to both parasite and host cells, i.e., macrophages and dendritic cells. The csPcs that targeted to mitochondria were more photolytic than those restricted to the endocytic compartments. Treatment of infected cells with endocytic csPcs resulted in their accumulation in Leishmania-containing phagolysosomes, indicative of reaching their target for photodynamic therapy, although their parasite versus host specificity is limited to a narrow range of csPc concentrations. In contrast, Leishmania pre-loaded with csPc were selectively photolyzed intracellularly, leaving host cells viable. Pre-illumination of such csPc-loaded Leishmania did not hinder their infectivity, but ensured their intracellular lysis. Ovalbumin (OVA) so delivered by photo-inactivated OVA transfectants to mouse macrophages and dendritic cells were co-presented with MHC Class I molecules by these antigen presenting cells to activate OVA epitope-specific CD8+T cells. The in vitro evidence presented here demonstrates for the first time not only the potential of endocytic csPcs for effective photodynamic therapy against Leishmania but also their utility in photo-inactivation of Leishmania to produce a safe carrier to express and deliver a defined antigen with enhanced cell-mediated immunity

    Predictors of stable return-to-work in non-acute, non-specific spinal pain: low total prior sick-listing, high self prediction and young age. A two-year prospective cohort study

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    <p>Abstract</p> <p>Background</p> <p>Non-specific spinal pain (NSP), comprising back and/or neck pain, is one of the leading disorders in long-term sick-listing. During 2000-2004, 125 Swedish primary-care patients with non-acute NSP, full-time sick-listed 6 weeks-2 years, were included in a randomized controlled trial to compare a cognitive-behavioural programme with traditional primary care. This prospective cohort study is a re-assessment of the data from the randomized trial with the 2 treatment groups considered as a single cohort. The aim was to investigate which baseline variables predict a stable return-to-work during a 2-year period after baseline: objective variables from function tests, socioeconomic, subjective and/or treatment variables. Stable return-to-work was a return-to-work lasting for at least 1 month from the start of follow-up.</p> <p>Methods</p> <p><it>Stable return-to-work </it>was the outcome variable, the above-mentioned factors were the predictive variables in multiple-logistic regression models, one per follow-up at 6, 12, 18 and 24 months after baseline. The factors from univariate analyzes with a <it>p</it>-value of at most .10 were included. The non-significant variables were excluded stepwise to yield models comprising only significant factors (<it>p </it>< .05). As the comparatively few cases made it risky to associate certain predictors with certain time-points, we finally considered the predictors which were represented in at least 3 follow-ups. They are presented with odds ratios (OR) and 95% confidence intervals.</p> <p>Results</p> <p>Three variables qualified, all of them represented in 3 follow-ups: <it>Low total prior sick-listing </it>(including all diagnoses) was the strongest predictor in 2 follow-ups, 18 and 24 months, OR 4.8 [1.9-12.3] and 3.8 [1.6-8.7] respectively, <it>High self prediction </it>(the patients' own belief in return-to-work) was the strongest at 12 months, OR 5.2 [1.5-17.5] and <it>Young age </it>(max 44 years) the second strongest at 18 months, OR 3.5 [1.3-9.1].</p> <p>Conclusions</p> <p>In primary-care patients with non-acute NSP, the strong predictors of stable return-to-work were 2 socioeconomic variables, <it>Low total prior sick-listing </it>and <it>Young age</it>, and 1 subjective variable, <it>High self-prediction</it>. Objective variables from function tests and treatment variables were non-predictors. Except for <it>Young age</it>, the predictors have previously been insufficiently studied, and so our study should widen knowledge within clinical practice.</p> <p>Trial registration</p> <p>Trial registration number for the original trial NCT00488735.</p
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