729 research outputs found
Characterization of Protective Human CD4+CD25+ FOXP3+ Regulatory T Cells Generated with IL-2, TGF-ÎČ and Retinoic Acid
BACKGROUND: Protective CD4+CD25+ regulatory T cells bearing the Forkhead Foxp3 transcription factor can now be divided into three subsets: Endogenous thymus-derived cells, those induced in the periphery, and another subset induced ex-vivo with pharmacological amounts of IL-2 and TGF-ÎČ. Unfortunately, endogenous CD4+CD25+ regulatory T cells are unstable and can be converted to effector cells by pro-inflammatory cytokines. Although protective Foxp3+CD4+CD25+ cells resistant to proinflammatory cytokines have been generated in mice, in humans this result has been elusive. Our objective, therefore, was to induce human naĂŻve CD4+ cells to become stable, functional CD25+ Foxp3+ regulatory cells that were also resistant to the inhibitory effects of proinflammatory cytokines. METHODOLOGY/PRINCIPAL FINDINGS: The addition of the vitamin A metabolite, all-trans retinoic acid (atRA) to human naĂŻve CD4+ cells suboptimally activated with IL-2 and TGF-ÎČ enhanced and stabilized FOXP3 expression, and accelerated their maturation to protective regulatory T cells. AtRA, by itself, accelerated conversion of naĂŻve to mature cells but did not induce FOXP3 or suppressive activity. The combination of atRA and TGF-ÎČ enabled CD4+CD45RA+ cells to express a phenotype and trafficking receptors similar to natural Tregs. AtRA/TGF-ÎČ-induced CD4+ regs were anergic and low producers of IL-2. They had potent in vitro suppressive activity and protected immunodeficient mice from a human-anti-mouse GVHD as well as expanded endogenous Tregs. However, treatment of endogenous Tregs with IL-1ÎČ and IL-6 decreased FOXP3 expression and diminished their protective effects in vivo while atRA-induced iTregs were resistant to these inhibitory effects. CONCLUSIONS/SIGNIFICANCE: We have developed a methodology that induces human CD4(+) cells to rapidly become stable, fully functional suppressor cells that are also resistant to proinflammatory cytokines. This methodology offers a practical novel strategy to treat human autoimmune diseases and prevent allograft rejection without the use of agents that kill cells or interfere with signaling pathways
"Resurrection of clinical efficacy" after resistance to endocrine therapy in metastatic breast cancer
BACKGROUND: In a significant proportion of metastatic breast cancer (MBC) patients whose tumour has progressed within 6 months of endocrine therapy (de novo resistance), it is generally believed that the chance of achieving clinical benefit (CB) with further endocrine therapy is minimal. METHODS: Data was retrieved from a prospectively updated database of metastatic breast cancer. Relevant data was exported to SPSSâą software for statistical analysis. RESULTS: In oestrogen receptor (ER) positive MBC patients with assessable disease, CB was achieved in 159 (71.3%) (1(st )line) patients. When these patients were put on further endocrine therapy, the CB rates were 63.2% (on 2(nd )line), 46.1% (on 3(rd )line) and 20% (on 4(th )line) with a median duration of response (DOR) in those with CB of 22, 12, 11 and 15 months respectively. The remaining 64(28.7%) patients had de novo resistance on 1(st )line endocrine therapy. Seventeen of these patients were treated with further endocrine therapy. The CB rates were 29.4% (on 2(nd )line) and 22.2% (on 3(rd )line) with a median DOR in those with CB of 22.7 months and 14 months respectively. CONCLUSION: The chance of further endocrine response continues to decrease with each line of therapy, yet CB is still seen with reasonable duration even with a 4(th )line agent. In addition, further endocrine response, with long duration, can be seen in a significant proportion of patients who have developed de novo resistance to 1(st )line endocrine therapy. The use of further endocrine therapy should not be excluded under these circumstances
Examining intra-rater and inter-rater response agreement: A medical chart abstraction study of a community-based asthma care program
<p>Abstract</p> <p>Background</p> <p>To assess the intra- and inter-rater agreement of chart abstractors from multiple sites involved in the evaluation of an Asthma Care Program (ACP).</p> <p>Methods</p> <p>For intra-rater agreement, 110 charts randomly selected from 1,433 patients enrolled in the ACP across eight Ontario communities were re-abstracted by 10 abstractors. For inter-rater agreement, data abstractors reviewed a set of eight fictitious charts. Data abstraction involved information pertaining to six categories: physical assessment, asthma control, spirometry, asthma education, referral visits, and medication side effects. Percentage agreement and the kappa statistic (Îș) were used to measure agreement. Sensitivity and specificity estimates were calculated comparing results from all raters against the gold standard.</p> <p>Results</p> <p>Intra-rater re-abstraction yielded an overall kappa of 0.81. Kappa values for the chart abstraction categories were: physical assessment (Îș 0.84), asthma control (Îș 0.83), spirometry (Îș 0.84), asthma education (Îș 0.72), referral visits (Îș 0.59) and medication side effects (Îș 0.51). Inter-rater abstraction of the fictitious charts produced an overall kappa of 0.75, sensitivity of 0.91 and specificity of 0.89. Abstractors demonstrated agreement for physical assessment (Îș 0.88, sensitivity and specificity 0.95), asthma control (Îș 0.68, sensitivity 0.89, specificity 0.85), referral visits (Îș 0.77, sensitivity 0.88, specificity 0.95), and asthma education (Îș 0.49, sensitivity 0.87, specificity 0.77).</p> <p>Conclusion</p> <p>Though collected by multiple abstractors, the results show high sensitivity and specificity and substantial to excellent inter- and intra-rater agreement, assuring confidence in the use of chart abstraction for evaluating the ACP.</p
Interregional correlations of glucose metabolism between the basal ganglia and different cortical areas: an ultra-high resolution PET/MRI fusion study using 18F-FDG
A physiologically based kinetic model for elucidating the in vivo distribution of administered mesenchymal stem cells
Although mesenchymal stem cells (MSCs) present a promising tool in cell therapy for the treatment of various diseases, the in vivo distribution of administered MSCs has still been poorly understood, which hampers the precise prediction and evaluation of their therapeutic efficacy. Here, we developed the first model to characterize the physiological kinetics of administered MSCs based on direct visualization of cell spatiotemporal disposition by intravital microscopy and assessment of cell quantity using flow cytometry. This physiologically based kinetic model was validated with multiple external datasets, indicating potential inter-route and inter-species predictive capability. Our results suggest that the targeting efficiency of MSCs is determined by the lung retention and interaction between MSCs and target organs, including cell arrest, depletion and release. By adapting specific parameters, this model can be easily applied to abnormal conditions or other types of circulating cells for designing treatment protocols and guiding future experiments
Absence of progesterone receptor associated with secondary breast cancer in postmenopausal women
The relationship between expression of receptors for oestrogen and progesterone (ER and PR) and disease progression in breast cancer was investigated by comparing immunocytochemical determinations of ER and PR in fine needle aspirates from primary and secondary breast tumours. Rates of receptor expression were significantly higher in primary than in secondary lesions: for ER 63.3% (n = 689) compared with 45.3% (n = 223), and for PR 53.7% (n = 443) compared with 33.1% (n = 121). The effect of menopausal status was examined by subdividing the patient cohort into those over or under the age of 50 years. In both instances, ER expression in secondary tumours was relatively low; however, only postmenopausal patients had significantly lower rates of PR expression in secondary tumours. Consistent with this, an increase in the ER+PRâ profile in secondary tumours compared with primary cases from postmenopausal patients was seen, and in a multivariate analysis, a specific absence of PR expression in secondary tumours was revealed. Comparison of ER and PR expression in simultaneously sampled primary tumours and lymph node metastases from the same patient showed that receptor expression was stable with progression to a metastatic site as results were concordant for ER in 92% (n = 88) and PR in 93.8% of cases (n = 65). These results suggest that absence of PR expression in primary breast cancer is associated with disease progression and may be a marker of an aggressive tumour phenotype. © 1999 Cancer Research Campaig
The progestational and androgenic properties of medroxyprogesterone acetate: gene regulatory overlap with dihydrotestosterone in breast cancer cells
INTRODUCTION: Medroxyprogesterone acetate (MPA), the major progestin used for oral contraception and hormone replacement therapy, has been implicated in increased breast cancer risk. Is this risk due to its progestational or androgenic properties? To address this, we assessed the transcriptional effects of MPA as compared with those of progesterone and dihydrotestosterone (DHT) in human breast cancer cells. METHOD: A new progesterone receptor-negative, androgen receptor-positive human breast cancer cell line, designated Y-AR, was engineered and characterized. Transcription assays using a synthetic promoter/reporter construct, as well as endogenous gene expression profiling comparing progesterone, MPA and DHT, were performed in cells either lacking or containing progesterone receptor and/or androgen receptor. RESULTS: In progesterone receptor-positive cells, MPA was found to be an effective progestin through both progesterone receptor isoforms in transient transcription assays. Interestingly, DHT signaled through progesterone receptor type B. Expression profiling of endogenous progesterone receptor-regulated genes comparing progesterone and MPA suggested that although MPA may be a somewhat more potent progestin than progesterone, it is qualitatively similar to progesterone. To address effects of MPA through androgen receptor, expression profiling was performed comparing progesterone, MPA and DHT using Y-AR cells. These studies showed extensive gene regulatory overlap between DHT and MPA through androgen receptor and none with progesterone. Interestingly, there was no difference between pharmacological MPA and physiological MPA, suggesting that high-dose therapeutic MPA may be superfluous. CONCLUSION: Our comparison of the gene regulatory profiles of MPA and progesterone suggests that, for physiologic hormone replacement therapy, the actions of MPA do not mimic those of endogenous progesterone alone. Clinically, the complex pharmacology of MPA not only influences its side-effect profile; but it is also possible that the increased breast cancer risk and/or the therapeutic efficacy of MPA in cancer treatment is in part mediated by androgen receptor
Differential requirements for the canonical NF-ÎșB transcription factors c-REL and RELA during the generation and activation of mature B cells
Signaling through the canonical nuclear factorâÎșB (NFâÎșB) pathway is critical for the generation and maintenance of mature B cells and for antigenâdependent Bâcell activation. câREL (rel) and RELA (rela) are the downstream transcriptional activators of the canonical NFâÎșB pathway. Studies of B cells derived from constitutional rel knockout mice and chimeric mice repopulated with relaâ/â fetal liver cells provided evidence that the subunits can have distinct roles during Bâcell development. However, the B cellâintrinsic functions of câREL and RELA during Bâcell generation and antigenâdependent Bâcell activation have not been determined in vivo. To clarify this issue, we crossed mice with conditional rel and rela alleles individually or in combination to mice that express Creârecombinase in B cells. We here report that, whereas single deletion of rel or rela did not impair mature Bâcell generation and maintenance, their simultaneous deletion led to a dramatic reduction of follicular and marginal zone B cells. Upon T cellâdependent immunization, B cellâspecific deletion of the câREL subunit alone abrogated the formation of germinal centers (GCs), whereas rela deletion did not affect GC formation. Tâindependent responses were strongly impaired in mice with B cellâspecific deletion of rel, and only modestly in mice with RELAâdeficient B cells. Our findings identify differential requirements for the canonical NFâÎșB subunits câREL and RELA at distinct stages of mature Bâcell development. The subunits are jointly required for the generation of mature B cells. During antigenâdependent Bâcell activation, câREL is the critical subunit required for the initiation of the GC reaction and for optimal Tâindependent antibody responses, with RELA being largely dispensable at this stage
A proposal for a coordinated effort for the determination of brainwide neuroanatomical connectivity in model organisms at a mesoscopic scale
In this era of complete genomes, our knowledge of neuroanatomical circuitry
remains surprisingly sparse. Such knowledge is however critical both for basic
and clinical research into brain function. Here we advocate for a concerted
effort to fill this gap, through systematic, experimental mapping of neural
circuits at a mesoscopic scale of resolution suitable for comprehensive,
brain-wide coverage, using injections of tracers or viral vectors. We detail
the scientific and medical rationale and briefly review existing knowledge and
experimental techniques. We define a set of desiderata, including brain-wide
coverage; validated and extensible experimental techniques suitable for
standardization and automation; centralized, open access data repository;
compatibility with existing resources, and tractability with current
informatics technology. We discuss a hypothetical but tractable plan for mouse,
additional efforts for the macaque, and technique development for human. We
estimate that the mouse connectivity project could be completed within five
years with a comparatively modest budget.Comment: 41 page
Combined PbâSr isotopic analysis in provenancing late Roman iron raw materials in the territory of Sagalassos (SW Turkey)
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