A cohort study of the recovery of health and wellbeing following colorectal cancer (CREW study): protocol paper

Background: the number of people surviving colorectal cancer has doubled in recent years. While much of the literature suggests that most people return to near pre-diagnosis status following surgery for colorectal cancer, this literature has largely focused on physical side effects. Longitudinal studies in colorectal cancer have either been small scale or taken a narrow focus on recovery after surgery. There is a need for a comprehensive, long-term study exploring all aspects of health and wellbeing in colorectal cancer patients. The aim of this study is to establish the natural history of health and wellbeing in people who have been treated for colorectal cancer. People have different dispositions, supports and resources, likely resulting in individual differences in restoration of health and wellbeing. The protocol described in this paper is of a study which will identify who is most at risk of problems, assess how quickly people return to a state of subjective health and wellbeing, and will measure factors which influence the course of recovery. Methods: this is a prospective, longitudinal cohort study following 1000 people with colorectal cancer over a period of two years, recruiting from 30 NHS cancer treatment centres across the UK. Questionnaires will be administered prior to surgery, and 3, 9, 15 and 24 months after surgery, with the potential to return to this cohort to explore on-going issues related to recovery after cancer. Discussion: outcomes will help inform health care providers about what helps or hinders rapid and effective recovery from cancer, and identify areas for intervention development to aid this process. Once established the cohort can be followed up for longer periods and be approached to participate in related projects as appropriate and subject to funding<br/

Effects of Video Enhancement in a Stated-Choice Experiment on Medical Decision Making

Background. The internet can be useful in administering stated-choice experiments to understand medical decision making and refine the content of patient decision aids. In internet-based stated-choice experiments, video and audio files can be used to provide information to respondents. Quality of data may or may not be affected. Objectives. In a methodological experiment concerned with administration of a stated-choice experiment on the internet concerned with knee-replacement surgery, we compared the data quality obtained with video-enhanced and conventional text formats. Methods. Members of the RAND Corporation’s American Life Panel and 50 years of age or older (n=1616) were randomly assigned to one of two survey modes: video (80%) or text (20%). Quality of data was measured by both the frequency of respondent speeding and plausibility of respondent choices. Results. Typical respondents completed the research task much more rapidly in the text condition than the video condition (10.6 versus 16.4 minutes). The choices were 5 to 10% more likely to be plausible for those in the video-enhanced condition than for those in the text version. The mode of administration did not affect respondents in the extent of their reported interest in the survey or in the degree to which they reported identifying with patients in vignettes. Conclusions. The advantages of the video enhancement in engaging respondents appeared to be offset by the greater time demands on respondents. Video-enhancements in stated-choice experiments may be most useful when used selectively to deliver information that cannot be delivered adequately by text

Social networks, decision aids, and patient decisions regarding knee-replacement surgery

Objective: Examine how information from social networks is associated with patient decisions in the presence of information from multiple professional sources including decision aids. Methods: We conducted a stated-choice experiment in which respondents made recommendations for hypothetical patients about whether full knee-replacement surgery should be performed to treat knee osteoarthritis. In addition, we administered a background questionnaire in which we explicitly asked respondents about the experience of people in their social network with knee osteoarthritis and possible treatment options. We examined the manner in which respondents’ recommendations for vignette persons were associated with the experiences of members of their own social networks. Results: Controlling for the information obtained from professional sources, satisfaction with full knee-replacement surgery within the respondents’ social networks was strongly associated with respondent decisions. Conclusion: Information from the social network may complement or compete with information from professional sources as patients make decisions. Practice Implications: Professionals should offer to assist patients in making sound use information they obtain from their social networks

Design and Testing of a Low-Cost and Low-Maintenance Drip Irrigation Filtration System for Micro-Irrigation in Developing Countries

The cylindrical filters presently used in <1000 m2 drip irrigation systems are frequently clogged, increasing pressure loss and lowering the flow rate through the filters. This work investigates the mechanisms for this clogging and proposes an alternative filtration design that would enable both more reliable and lower maintenance filtering. This proposed system is compatible with existing drip irrigation systems and could be made inexpensively with plastic bottle manufacturing equipment. To compare the proposed design to off-the-shelf options, a drip irrigation test setup was built to measure the pressure loss across different filters as particles accumulated. These experiments confirmed that pleated cartridge filters, with high effective surface area, incurred lower pressure losses than cylindrical filters. These tests revealed that the greatest reason for clogged performance was that filtered particles (not the cartridge filter itself) eventually restricted the flow of water through the system. This inspired the redesign of the filter housing such that the housing extended far below the filter, providing a catch basin away from the filter for the particles to settle. Fixing the filter independently of the bottom casing significantly improved the overall performance of the filtration system, reduced the maintenance requirement necessary from the user, and would enable inexpensive manufacturing via blow molding. This paper experimentally demonstrates that the cartridge filter inside the redesigned housing can filter out over 2 kg of sand while maintaining less than a .03 bar pressure drop across the filter at a flow rate of 25 l/s.Massachusetts Institute of Technology. Tata Center for Technology and DesignMassachusetts Institute of Technology. Department of Mechanical Engineerin

Delivering a low-cost, reliable drip irrigation filtration system for micro-irrigation in developing countries

The cylindrical filters presently used in drip irrigation systems frequently clog, increasing pressure loss and lowering the flow rate through the filters. This work investigates alternative filtration strategies that increase the reliability of, and are compatible with, existing systems. To test different filtration strategies, a drip irrigation test setup was built to measure the pressure loss across different filters as particles accumulated. These experiments found that pleated cartridge filters, with high effective surface area, incurred the lowest pressure losses. More significantly, it was observed during these tests that the filtered out particles settled to the bottom of the filter housing when flow through the filter ceased. This inspired the redesign of the filter housing such that the housing extended far below the filter, providing a catch basin away from the filter for the particles to settle. Fixing the filter independently of the bottom casing significantly improves the overall performance of the filtration system and can be inexpensively manufactured via blow molding. This paper experimentally demonstrates that the cartridge filter inside the redesigned housing can filter out over 2 kg of sand while maintaining less than a .03 bar pressure drop across the filter at a flow rate of 25 l/s.MIT Tata Center for Technology and DesignMassachusetts Institute of Technology. Department of Mechanical EngineeringInternational Development Enterprise

Using Internet‐Based Vignette Methods to Understand Elder Residential Choices

This paper illustrates an innovative method of administering fractional factorial surveys (vignettes) using the internet. The approach makes it possible to use video clips to deliver information. The method also provides subjects with interactive options before making judgments. A study to determine the views of older people regarding residential options is used to illustrate the method. The study found that the following characteristics of vignette persons affected subject recommendations: personal introduction, functional status, social network, and current housing characteristics. However, characteristics of retirement community features and personal financial status did not affect recommendations

Increased expression of a microRNA correlates with anthelmintic resistance in parasitic nematodes

Resistance to anthelmintic drugs is a major problem in the global fight against parasitic nematodes infecting humans and animals. While previous studies have identified mutations in drug target genes in resistant parasites, changes in the expression levels of both targets and transporters have also been reported. The mechanisms underlying these changes in gene expression are unresolved. Here, we take a novel approach to this problem by investigating the role of small regulatory RNAs in drug resistant strains of the important parasite Haemonchus contortus. microRNAs (miRNAs) are small (22 nt) non-coding RNAs that regulate gene expression by binding predominantly to the 3′ UTR of mRNAs. Changes in miRNA expression have been implicated in drug resistance in a variety of tumor cells. In this study, we focused on two geographically distinct ivermectin resistant strains of H. contortus and two lines generated by multiple rounds of backcrossing between susceptible and resistant parents, with ivermectin selection. All four resistant strains showed significantly increased expression of a single miRNA, hco-miR-9551, compared to the susceptible strain. This same miRNA is also upregulated in a multi-drug-resistant strain of the related nematode Teladorsagia circumcincta. hco-miR-9551 is enriched in female worms, is likely to be located on the X chromosome and is restricted to clade V parasitic nematodes. Genes containing predicted binding sites for hco-miR-9551 were identified computationally and refined based on differential expression in a transcriptomic dataset prepared from the same drug resistant and susceptible strains. This analysis identified three putative target mRNAs, one of which, a CHAC domain containing protein, is located in a region of the H. contortus genome introgressed from the resistant parent. hco-miR-9551 was shown to interact with the 3′ UTR of this gene by dual luciferase assay. This study is the first to suggest a role for miRNAs and the genes they regulate in drug resistant parasitic nematodes. miR-9551 also has potential as a biomarker of resistance in different nematode species

Choosing among residential options: Results of a vignette experiment

Older people who experience declining health are often faced with difficult decisions about possible residential relocation. The research aim was to determine how five distinct dimensions-functional status, features of current housing, social networks, features of retirement communities, and financial considerations-affect decisions to relocate to a retirement community. A vignette experiment with a factorial design was conducted involving both older people and adult children who were concerned with an aging parent. Use of the Internet for administration of the experiment made it possible to deliver information to research participants through video clips. Research participants were influenced by each of the dimensions; however, functional status of the vignette persons had the greatest impact, and financial considerations the least. Adult children were more likely to recommend moves than were older people. The research is suggestive of the potential for use of vignette experiments for a fuller understanding of relocation decisions

Using the internet to administer more realistic vignette experiments

This article illustrates an innovative method of administering stated choice studies (or vignette experiments) using computers and the Internet. The use of video clips to deliver information to research participants makes vignettes more realistic, helps to engage interest of research participants, and can reduce framing effects. The method also provides research participants with interactive options before making judgments. A study to determine the views of older people regarding residential options is used to illustrate the method. Even older people with limited experience in using computers participated successfully. The study findings showed that research participants responded both to the audiovisual characteristics of vignette persons and to the variables in the vignette structure

How the structure of the large subunit controls function in an oxygen-tolerant [NiFe]-hydrogenase

Salmonella enterica is an opportunistic pathogen that produces a [NiFe]-hydrogenase under aerobic conditions. In the present study, genetic engineering approaches were used to facilitate isolation of this enzyme, termed Hyd-5. The crystal structure was determined to a resolution of 3.2 Å and the hydro-genase was observed to comprise associated large and small subunits. The structure indicated that His(229) from the large subunit was close to the proximal [4Fe–3S] cluster in the small subunit. In addition, His(229) was observed to lie close to a buried glutamic acid (Glu(73)), which is conserved in oxygen-tolerant hydrogenases. His(229) and Glu(73) of the Hyd-5 large subunit were found to be important in both hydrogen oxidation activity and the oxygen-tolerance mechanism. Substitution of His(229) or Glu(73) with alanine led to a loss in the ability of Hyd-5 to oxidize hydrogen in air. Furthermore, the H229A variant was found to have lost the overpotential requirement for activity that is always observed with oxygen-tolerant [NiFe]-hydrogenases. It is possible that His(229) has a role in stabilizing the super-oxidized form of the proximal cluster in the presence of oxygen, and it is proposed that Glu(73)could play a supporting role in fine-tuning the chemistry of His(229) to enable this function