Optimized CRISPR-mediated gene knockin reveals FOXP3-independent maintenance of human Treg identity

Regulatory T cell (Treg) therapy is a promising curative approach for a variety of immune-mediated conditions. CRISPR-based genome editing allows precise insertion of transgenes through homology-directed repair, but its use in human Tregs has been limited. We report an optimized protocol for CRISPR-mediated gene knockin in human Tregs with high-yield expansion. To establish a benchmark of human Treg dysfunction, we target the master transcription factor FOXP3 in naive and memory Tregs. Although FOXP3-ablated Tregs upregulate cytokine expression, effects on suppressive capacity in vitro manifest slowly and primarily in memory Tregs. Moreover, FOXP3-ablated Tregs retain their characteristic protein, transcriptional, and DNA methylation profile. Instead, FOXP3 maintains DNA methylation at regions enriched for AP-1 binding sites. Thus, although FOXP3 is important for human Treg development, it has a limited role in maintaining mature Treg identity. Optimized gene knockin with human Tregs will enable mechanistic studies and the development of tailored, next-generation Treg cell therapies

Techno-economic evaluation of reducing shielding gas consumption in GMAW whilst maintaining weld quality

A new method of supplying shielding gases in an alternating manner has been developed to enhance the efficiency of conventional gas metal arc welding (GMAW). However, the available literature on this advanced joining process is very sparse and no cost evaluation has been reported to date. In simple terms, the new method involves discretely supplying two different shielding gases to the weld pool at predetermined frequencies which creates a dynamic action within the liquid pool. In order to assess the potential benefits of this new method from a technical and cost perspective, a comparison has been drawn between the standard shielding gas composition of Ar/20%CO2, which is commonly used in UK and European shipbuilding industries for carbon steels, and a range of four different frequencies alternating between Ar/20%CO2 and helium. The beneficial effects of supplying the weld shielding gases in an alternating manner were found to provide attractive benefits for the manufacturing community. For example, the present study showed that compared with conventional GMAW, a 17 per cent reduction in total welding cost was achieved in the case of the alternating gas method and savings associated with a reduction in the extent of post-weld straightening following plate distortion were also identified. Also, the mechanical properties of the alternating case highlighted some marginal improvements in strength and Charpy impact toughness which were attributed to a more refined weld microstructure

Development of the measure of ovarian symptoms and treatment concerns: aiming for optimal measurement of patient-reported symptom benefit with chemotherapy for symptomatic ovarian cancer

OBJECTIVE: The aim of this study was to determine the optimal patient-reported outcome measure (PROM) for assessing symptom benefit in trials of palliative chemotherapy for women with symptomatic ovarian cancer. METHODS: Candidate PROMs were EORTC QLQ-C30 plus ovarian-specific QLQ-OV28, Functional Assessment of Cancer Therapy-Ovarian (FACT-O), FACT Ovarian Symptom Index (FOSI), and gynecologic cancer-specific Symptom Representation Questionnaire. Predefined optimality criteria were inclusion of all symptoms necessary for the specified purpose, recall period covering typical length of palliative chemotherapy, numerical item rating scales, and all necessary symptoms included in a single symptom index. Qualitative and quantitative methods were applied to data from stage 1 of the Gynecologic Cancer Intergroup Symptom Benefit Study to determine the set of necessary symptoms and to objectively assess candidate PROMs against the optimality criteria. RESULTS: Ten necessary symptoms were identified: pain, fatigue, abdominal bloating/discomfort, sleep disturbance, bowel disturbance, nausea and vomiting, shortness of breath, poor appetite, urinary symptoms, and weight changes. Although QLQ-C30 and QLQ-OV28 together cover all these symptoms, they split them into numerous scales, dissipating potential symptom-benefit signal. Conversely, FACT-O does not cover all necessary symptoms and contains many other HRQoL-related items and treatment side effects, diluting potential symptom-benefit signal when summed into scales. Item response scales and composite scoring of all candidate PROMs were suboptimal to our specific purpose. We therefore developed a new PROM, the Measure of Ovarian Symptoms and Treatment (MOST) concerns, to provide optimal measurement for the specified purpose. CONCLUSIONS: This article documents the development of the MOST, a new PROM designed to assess patient-reported benefits and burden as end points in clinical trials of palliative chemotherapy for women with symptomatic ovarian cancer. The validity, reliability, and statistical efficiency of the MOST, relative to the best candidate scales of existing PROMs, will be assessed in the stage 2 of Gynecologic Cancer Intergroup Symptom Benefit Study

The potential of a new larviciding method for the control of malaria vectors

Malaria pathogens are transmitted to humans by the bite of female Anopheles mosquitoes. The juvenile stages of these mosquitoes develop in a variety of water bodies and are key targets for vector control campaigns involving the application of larvicides. The effective operational implementation of these campaigns is difficult, time consuming, and expensive. New evidence however, suggests that adult mosquitoes can be co-opted into disseminating larvicides in a far more targeted and efficient manner than can be achieved using conventional methods

A Spatial Model of Mosquito Host-Seeking Behavior

Mosquito host-seeking behavior and heterogeneity in host distribution are important factors in predicting the transmission dynamics of mosquito-borne infections such as dengue fever, malaria, chikungunya, and West Nile virus. We develop and analyze a new mathematical model to describe the effect of spatial heterogeneity on the contact rate between mosquito vectors and hosts. The model includes odor plumes generated by spatially distributed hosts, wind velocity, and mosquito behavior based on both the prevailing wind and the odor plume. On a spatial scale of meters and a time scale of minutes, we compare the effectiveness of different plume-finding and plume-tracking strategies that mosquitoes could use to locate a host. The results show that two different models of chemotaxis are capable of producing comparable results given appropriate parameter choices and that host finding is optimized by a strategy of flying across the wind until the odor plume is intercepted. We also assess the impact of changing the level of host aggregation on mosquito host-finding success near the end of the host-seeking flight. When clusters of hosts are more tightly associated on smaller patches, the odor plume is narrower and the biting rate per host is decreased. For two host groups of unequal number but equal spatial density, the biting rate per host is lower in the group with more individuals, indicative of an attack abatement effect of host aggregation. We discuss how this approach could assist parameter choices in compartmental models that do not explicitly model the spatial arrangement of individuals and how the model could address larger spatial scales and other probability models for mosquito behavior, such as Lévy distributions

The impact of Cochrane Systematic Reviews : a mixed method evaluation of outputs from Cochrane Review Groups supported by the UK National Institute for Health Research

© 2014 Bunn et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: There has been a growing emphasis on evidence-informed decision making in health care. Systematic reviews, such as those produced by the Cochrane Collaboration, have been a key component of this movement. The UK National Institute for Health Research (NIHR) Systematic Review Programme currently supports 20 Cochrane Review Groups (CRGs). The aim of this study was to identify the impacts of Cochrane reviews published by NIHR funded CRGs during the years 2007-11. Methods: We sent questionnaires to CRGs and review authors, interviewed guideline developers and used bibliometrics and documentary review to get an overview of CRG impact and to evaluate the impact of a sample of 60 Cochrane reviews. We used a framework with four categories (knowledge production, research targeting, informing policy development, and impact on practice/services). Results: A total of 1502 new and updated reviews were produced by the 20 NIHR funded CRGs between 2007-11. The clearest impacts were on policy with a total of 483 systematic reviews cited in 247 sets of guidance; 62 were international, 175 national (87 from the UK) and 10 local. Review authors and CRGs provided some examples of impact on practice or services, for example safer use of medication, the identification of new effective drugs or treatments and potential economic benefits through the reduction in the use of unproven or unnecessary procedures. However, such impacts are difficult to objectively document and the majority of reviewers were unsure if their review had produced specific impacts. Qualitative data suggested that Cochrane reviews often play an instrumental role in informing guidance although a poor fit with guideline scope or methods, reviews being out of date and a lack of communication between CRGs and guideline developers were barriers to their use. Conclusions: Health and economic impacts of research are generally difficult to measure. We found that to be the case with this evaluation. Impacts on knowledge production and clinical guidance were easier to identify and substantiate than those on clinical practice. Questions remain about how we define and measure impact and more work is needed to develop suitable methods for impact analysis.Peer reviewe

Using a New Odour-Baited Device to Explore Options for Luring and Killing Outdoor-Biting Malaria Vectors: A Report on Design and Field Evaluation of the Mosquito Landing Box.

Mosquitoes that bite people outdoors can sustain malaria transmission even where effective indoor interventions such as bednets or indoor residual spraying are already widely used. Outdoor tools may therefore complement current indoor measures and improve control. We developed and evaluated a prototype mosquito control device, the 'Mosquito Landing Box' (MLB), which is baited with human odours and treated with mosquitocidal agents. The findings are used to explore technical options and challenges relevant to luring and killing outdoor-biting malaria vectors in endemic settings. Field experiments were conducted in Tanzania to assess if wild host-seeking mosquitoes 1) visited the MLBs, 2) stayed long or left shortly after arrival at the device, 3) visited the devices at times when humans were also outdoors, and 4) could be killed by contaminants applied on the devices. Odours suctioned from volunteer-occupied tents were also evaluated as a potential low-cost bait, by comparing baited and unbaited MLBs. There were significantly more Anopheles arabiensis, An. funestus, Culex and Mansonia mosquitoes visiting baited MLB than unbaited controls (P<=0.028). Increasing sampling frequency from every 120 min to 60 and 30 min led to an increase in vector catches of up to 3.6 fold (P<=0.002), indicating that many mosquitoes visited the device but left shortly afterwards. Outdoor host-seeking activity of malaria vectors peaked between 7:30 and 10:30pm, and between 4:30 and 6:00am, matching durations when locals were also outdoors. Maximum mortality of mosquitoes visiting MLBs sprayed or painted with formulations of candidate mosquitocidal agent (pirimiphos-methyl) was 51%. Odours from volunteer occupied tents attracted significantly more mosquitoes to MLBs than controls (P<0.001). While odour-baited devices such as the MLBs clearly have potential against outdoor-biting mosquitoes in communities where LLINs are used, candidate contaminants must be those that are effective at ultra-low doses even after short contact periods, since important vector species such as An. arabiensis make only brief visits to such devices. Natural human odours suctioned from occupied dwellings could constitute affordable sources of attractants to supplement odour baits for the devices. The killing agents used should be environmentally safe, long lasting, and have different modes of action (other than pyrethroids as used on LLINs), to curb the risk of physiological insecticide resistance