317 research outputs found
An optogenetic gene expression system with rapid activation and deactivation kinetics
Optogenetic gene expression systems can control transcription with spatial and temporal detail unequaled with traditional inducible promoter systems. However, current eukaryotic light-gated transcription systems are limited by toxicity, dynamic range, or slow activation/deactivation. Here we present an optogenetic gene expression system that addresses these shortcomings and demonstrate its broad utility. Our approach utilizes an engineered version of EL222, a bacterial Light-Oxygen-Voltage (LOV) protein that binds DNA when illuminated with blue light. The system has a large (\u3e100-fold) dynamic range of protein expression, rapid activation (\u3c 10 s) and deactivation kinetics (\u3c 50 s), and a highly linear response to light. With this system, we achieve light-gated transcription in several mammalian cell lines and intact zebrafish embryos with minimal basal gene activation and toxicity. Our approach provides a powerful new tool for optogenetic control of gene expression in space and time
Workflow to improve patient recruitment for clinical trials within hospital information systems – a case-study
<p>Abstract</p> <p>Background</p> <p>The identification of suitable patients is a common problem in clinical trials that is especially evident in tertiary care hospitals.</p> <p>Methods</p> <p>We developed and analysed a workflow, which uses routine data captured during patient care in a hospital information system (HIS), to identify potential trial subjects. Study nurses or physicians are notified automatically by email and verify eligibility.</p> <p>Results</p> <p>As a case study we implemented the system for acute myeloid leukemia (AML) trials in Münster. During a test period of 50 days 41 patients were identified by the system. 13 could be included as new trial patients, 7 were already included during earlier visits. According to review of paper records no AML trial patient was missed by the system. In addition, the hospital information system further allowed to preselect patients for specific trials based on their disease status and individual characteristics.</p> <p>Conclusion</p> <p>Routine HIS data can be used to support patient recruitment for clinical trials by means of an automated notification workflow.</p
Health care costs, utilization and patterns of care following Lyme disease
BACKGROUND:Lyme disease is the most frequently reported vector borne infection in the United States. The Centers for Disease Control have estimated that approximately 10% to 20% of individuals may experience Post-Treatment Lyme Disease Syndrome - a set of symptoms including fatigue, musculoskeletal pain, and neurocognitive complaints that persist after initial antibiotic treatment of Lyme disease. Little is known about the impact of Lyme disease or post-treatment Lyme disease symptoms (PTLDS) on health care costs and utilization in the United States. OBJECTIVES:1) to examine the impact of Lyme disease on health care costs and utilization, 2) to understand the relationship between Lyme disease and the probability of developing PTLDS, 3) to understand how PTLDS may impact health care costs and utilization. METHODS:This study utilizes retrospective data on medical claims and member enrollment for persons aged 0-64 years who were enrolled in commercial health insurance plans in the United States between 2006-2010. 52,795 individuals treated for Lyme disease were compared to 263,975 matched controls with no evidence of Lyme disease exposure. RESULTS:Lyme disease is associated with 3,798 higher total health care costs (95% CI: 3,542-4,055, p<.001) and 66% more outpatient visits (95% CI: 64%-69%, p<.001) over a 12-month period, relative to those with no PTLDS-related diagnoses. CONCLUSIONS:Lyme disease is associated with increased costs above what would be expected for an easy to treat infection. The presence of PTLDS-related diagnoses after treatment is associated with significant health care costs and utilization
A theory of organizational readiness for change
<p>Abstract</p> <p>Background</p> <p>Change management experts have emphasized the importance of establishing organizational readiness for change and recommended various strategies for creating it. Although the advice seems reasonable, the scientific basis for it is limited. Unlike individual readiness for change, organizational readiness for change has not been subject to extensive theoretical development or empirical study. In this article, I conceptually define organizational readiness for change and develop a theory of its determinants and outcomes. I focus on the organizational level of analysis because many promising approaches to improving healthcare delivery entail collective behavior change in the form of systems redesign--that is, multiple, simultaneous changes in staffing, work flow, decision making, communication, and reward systems.</p> <p>Discussion</p> <p>Organizational readiness for change is a multi-level, multi-faceted construct. As an organization-level construct, readiness for change refers to organizational members' shared resolve to implement a change (change commitment) and shared belief in their collective capability to do so (change efficacy). Organizational readiness for change varies as a function of how much organizational members value the change and how favorably they appraise three key determinants of implementation capability: task demands, resource availability, and situational factors. When organizational readiness for change is high, organizational members are more likely to initiate change, exert greater effort, exhibit greater persistence, and display more cooperative behavior. The result is more effective implementation.</p> <p>Summary</p> <p>The theory described in this article treats organizational readiness as a shared psychological state in which organizational members feel committed to implementing an organizational change and confident in their collective abilities to do so. This way of thinking about organizational readiness is best suited for examining organizational changes where collective behavior change is necessary in order to effectively implement the change and, in some instances, for the change to produce anticipated benefits. Testing the theory would require further measurement development and careful sampling decisions. The theory offers a means of reconciling the structural and psychological views of organizational readiness found in the literature. Further, the theory suggests the possibility that the strategies that change management experts recommend are equifinal. That is, there is no 'one best way' to increase organizational readiness for change.</p
No Evidence for a Trade-Off between Reproductive Investment and Immunity in a Rodent
Life history theory assumes there are trade-offs between competing functions such as reproduction and immunity. Although well studied in birds, studies of the trade-offs between reproduction and immunity in small mammals are scarce. Here we examined whether reduced immunity is a consequence of reproductive effort in lactating Brandt's voles (Lasiopodomys brandtii). Specifically, we tested the effects of lactation on immune function (Experiment I). The results showed that food intake and resting metabolic rate (RMR) were higher in lactating voles (6≤ litter size ≤8) than that in non-reproductive voles. Contrary to our expectation, lactating voles also had higher levels of serum total Immunoglobulin G (IgG) and anti-keyhole limpet hemocyanin (KLH) IgG and no change in phytohemagglutinin (PHA) response and anti-KLH Immunoglobulin M (IgM) compared with non-reproductive voles, suggesting improved rather than reduced immune function. To further test the effect of differences in reproductive investment on immunity, we compared the responses between natural large (n≥8) and small litter size (n≤6) (Experiment II) and manipulated large (11–13) and small litter size (2–3) (Experiment III). During peak lactation, acquired immunity (PHA response, anti-KLH IgG and anti-KLH IgM) was not significantly different between voles raising large or small litters in both experiments, despite the measured difference in reproductive investment (greater litter size, litter mass, RMR and food intake in the voles raising larger litters). Total IgG was higher in voles with natural large litter size than those with natural small litter size, but decreased in the enlarged litter size group compared with control and reduced group. Our results showed that immune function is not suppressed to compensate the high energy demands during lactation in Brandt's voles and contrasting the situation in birds, is unlikely to be an important aspect mediating the trade-off between reproduction and survival
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Biomineralisation by earthworms: an investigation into the stability and distribution of amorphous calcium carbonate
Background
Many biominerals form from amorphous calcium carbonate (ACC), but this phase is highly unstable when synthesised in its pure form inorganically. Several species of earthworm secrete calcium carbonate granules which contain highly stable ACC. We analysed the milky fluid from which granules form and solid granules for amino acid (by liquid chromatography) and functional group (by Fourier transform infrared (FTIR) spectroscopy) compositions. Granule elemental composition was determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and electron microprobe analysis (EMPA). Mass of ACC present in solid granules was quantified using FTIR and compared to granule elemental and amino acid compositions. Bulk analysis of granules was of powdered bulk material. Spatially resolved analysis was of thin sections of granules using synchrotron-based μ-FTIR and EMPA electron microprobe analysis.
Results
The milky fluid from which granules form is amino acid-rich (≤ 136 ± 3 nmol mg−1 (n = 3; ± std dev) per individual amino acid); the CaCO3 phase present is ACC. Even four years after production, granules contain ACC. No correlation exists between mass of ACC present and granule elemental composition. Granule amino acid concentrations correlate well with ACC content (r ≥ 0.7, p ≤ 0.05) consistent with a role for amino acids (or the proteins they make up) in ACC stabilisation. Intra-granule variation in ACC (RSD = 16%) and amino acid concentration (RSD = 22–35%) was high for granules produced by the same earthworm. Maps of ACC distribution produced using synchrotron-based μ-FTIR mapping of granule thin sections and the relative intensity of the ν2: ν4 peak ratio, cluster analysis and component regression using ACC and calcite standards showed similar spatial distributions of likely ACC-rich and calcite-rich areas. We could not identify organic peaks in the μ-FTIR spectra and thus could not determine whether ACC-rich domains also had relatively high amino acid concentrations. No correlation exists between ACC distribution and elemental concentrations determined by EMPA.
Conclusions
ACC present in earthworm CaCO3 granules is highly stable. Our results suggest a role for amino acids (or proteins) in this stability. We see no evidence for stabilisation of ACC by incorporation of inorganic components
Putative contribution of CD56 positive cells in cetuximab treatment efficacy in first-line metastatic colorectal cancer patients
Activity of cetuximab, a chimeric monoclonal antibody targeting the epidermal growth factor receptor, is largely attributed to its direct antiproliferative and proapoptotic effects. Antibody-dependent cell-mediated cytotoxicity (ADCC) could be another possible mechanism of cetuximab antitumor effects and its specific contribution on the clinical activity of cetuximab is unknown.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe
Pharmacogenetic profiling and cetuximab outcome in patients with advanced colorectal cancer
<p>Abstract</p> <p>Background</p> <p>We analyzed the influence of 8 germinal polymorphisms of candidate genes potentially related to EGFR signalling (<it>EGFR</it>, <it>EGF</it>, <it>CCND1</it>) or antibody-directed cell cytotoxicity (<it>FCGR2A </it>and <it>FCGR3A</it>) on outcome of colorectal cancer (CRC) patients receiving cetuximab-based therapy.</p> <p>Methods</p> <p>Fifty-eight advanced CRC patients treated with cetuximab-irinotecan salvage therapy between 2001 and 2007 were analyzed (mean age 60; 50 PS 0-1). The following polymorphisms were analyzed on blood DNA: <it>EGFR </it>(CA repeats in intron 1, -216 G > T, -191C > A, R497K), <it>EGF </it>(A61G), <it>CCND1 </it>(A870G), <it>FCGR2A </it>(R131H), <it>FCGR3A </it>(F158V). Statistical analyses were conducted on the total population and on patients with wt KRas tumors. All SNPs were considered as ternary variables (wt/wt <it>vs </it>wt/mut <it>vs </it>mut/mut), with the exception of -191C > A <it>EGFR </it>polymorphism (AA patient merged with CA patients).</p> <p>Results</p> <p>Analysis of skin toxicity as a function of EGFR intron 1 polymorphism showed a tendency for higher toxicity in patients with a low number of CA-repeats (p = 0.058). <it>CCND1 </it>A870G polymorphism was significantly related to clinical response, both in the entire population and in KRas wt patients, with the G allele being associated with a lack of response. In wt KRas patients, time to progression (TTP) was significantly related to <it>EGFR </it>-191C > A polymorphism with a longer TTP in CC patients as compared to others, and to <it>CCND1 </it>A870G polymorphism with the G allele being associated with a shorter TTP; a multivariate analysis including these two polymorphisms only retained <it>CCND1 </it>polymorphism. Overall survival was significantly related to <it>CCND1 </it>polymorphism with a shorter survival in patients bearing the G allele, and to <it>FCGR3A </it>F158V polymorphism with a shorter survival in VV patients (in the entire population and in KRas wt patients). <it>FCGR3A </it>F158V and <it>CCND1 </it>A870G polymorphisms were significant independent predictors of overall survival.</p> <p>Conclusions</p> <p>Present original data obtained in wt KRas patients corresponding to the current cetuximab-treated population clearly suggest that <it>CCND1 </it>A870G polymorphism may be used as an additional marker for predicting cetuximab efficacy, TTP and overall survival. In addition, <it>FCGR3A </it>F158V polymorphism was a significant independent predictor of overall survival.</p
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