Use of horseradish peroxidase for gene-directed enzyme prodrug therapy with paracetamol

Gene therapy is a potential method of treating cancer with a greater degree of targeting than conventional therapies. In addition, therapy can be directed towards cells within the tumour population that are traditionally resistant to current treatment schedules. Horseradish peroxidase (HRP) can oxidise paracetamol to N-acetyl-p-benzoquinoneimine via a one-electron pathway. Incubation of human cells expressing HRP with 0.5–10 mm paracetamol reduced clonogenic survival, but had little effect on control cells. A small increase in apoptosis was seen and a decrease in the number of cells undergoing mitosis, consistent with reports in hepatocytes using higher paracetamol concentrations. The cytotoxicity was also seen under conditions of severe hypoxia (catalyst induced anoxia), indicating that the HRP/paracetamol combination may be suitable for hypoxia-targeted gene therapy

A Qualitative Methodology for Studying Parent–Child Argumentation

This chapter provides a detailed exposé of the research methodology on which the investigation of parent–child argumentation during mealtime is based. In the first part, the conceptual tools adopted for the analysis of argumentative discussions between parents and children, i.e., the pragma-dialectical ideal model of a critical discussion and the Argumentum Model of Topics, are presented. Subsequently, the process of data gathering and the procedures for the transcription of oral data are discussed. Finally, in the last part of the chapter, ethical issues and practical problems in collecting parent–child mealtime conversations present throughout the study are considered

Clinicians' management strategies for patients with dyspepsia: a qualitative approach

BACKGROUND: Symptoms from the upper gastrointestinal tract are frequently encountered in clinical practice and may be of either organic or functional origin. For some of these conditions, according to the literature, certain management strategies can be recommended. For other conditions, the evidence is more ambiguous. The hypothesis that guided our study design was twofold: Management strategies and treatments suggested by different clinicians vary considerably, even when optimal treatment is clear-cut, as documented by evidence in the literature. Clinicians believe that the management strategies of their colleagues are similar to their own. METHODS: Simulated case histories of four patients with symptoms from the upper gastrointestinal tract were presented to 27 Swedish clinicians who were specialists in medical gastroenterology, surgery, and general practice and worked at three hospitals in the southern part of Sweden. The patients' histories contained information on the patient's sex and age and the localisation of the symptoms, but descriptions of subjective symptoms and findings from examinations differed from history to history. Interviews containing open-ended questions were conducted. RESULTS: For the same patient, the management strategies and treatments suggested by the clinicians varied widely, as did the strategies suggested by clinicians in the same speciality. Variation was more pronounced if the case history noted symptoms but no organic findings than if the case history noted unambiguous findings and symptoms. However, even in cases with a consensus in the scientific literature on treatment, the variations in clinicians' opinion on management were pronounced. CONCLUSION: Despite these variations, the clinicians believed that the decisions made by their colleagues would be similar to their own. The overall results of this study indicate that we as researchers must make scientific evidence comprehensible and communicate evidence so that clinicians are able to interpret and implement it in practice. Of particular significance is that scientific evidence leads to an evidence-based care which is effective clinical practice and to the promotion of health from the perspective of the patient, together with cost-effectiveness as a priority

A clonal expression biomarker associates with lung cancer mortality

An aim of molecular biomarkers is to stratify patients with cancer into disease subtypes predictive of outcome, improving diagnostic precision beyond clinical descriptors such as tumor stage1. Transcriptomic intratumor heterogeneity (RNA-ITH) has been shown to confound existing expression-based biomarkers across multiple cancer types2,3,4,5,6. Here, we analyze multi-region whole-exome and RNA sequencing data for 156 tumor regions from 48 patients enrolled in the TRACERx study to explore and control for RNA-ITH in non-small cell lung cancer. We find that chromosomal instability is a major driver of RNA-ITH, and existing prognostic gene expression signatures are vulnerable to tumor sampling bias. To address this, we identify genes expressed homogeneously within individual tumors that encode expression modules of cancer cell proliferation and are often driven by DNA copy-number gains selected early in tumor evolution. Clonal transcriptomic biomarkers overcome tumor sampling bias, associate with survival independent of clinicopathological risk factors, and may provide a general strategy to refine biomarker design across cancer types

Rapid Selection and Proliferation of CD133(+) Cells from Cancer Cell Lines: Chemotherapeutic Implications

Cancer stem cells (CSCs) are considered a subset of the bulk tumor responsible for initiating and maintaining the disease. Several surface cellular markers have been recently used to identify CSCs. Among those is CD133, which is expressed by hematopoietic progenitor cells as well as embryonic stem cells and various cancers. We have recently isolated and cultured CD133 positive [CD133(+)] cells from various cancer cell lines using a NASA developed Hydrodynamic Focusing Bioreactor (HFB) (Celdyne, Houston, TX). For comparison, another bioreactor, the rotary cell culture system (RCCS) manufactured by Synthecon (Houston, TX) was used. Both the HFB and the RCCS bioreactors simulate aspects of hypogravity. In our study, the HFB increased CD133(+) cell growth from various cell lines compared to the RCCS vessel and to normal gravity control. We observed a (+)15-fold proliferation of the CD133(+) cellular fraction with cancer cells that were cultured for 7-days at optimized conditions. The RCCS vessel instead yielded a (−)4.8-fold decrease in the CD133(+)cellular fraction respect to the HFB after 7-days of culture. Interestingly, we also found that the hypogravity environment of the HFB greatly sensitized the CD133(+) cancer cells, which are normally resistant to chemo treatment, to become susceptible to various chemotherapeutic agents, paving the way to less toxic and more effective chemotherapeutic treatment in patients. To be able to test the efficacy of cytotoxic agents in vitro prior to their use in clinical setting on cancer cells as well as on cancer stem cells may pave the way to more effective chemotherapeutic strategies in patients. This could be an important advancement in the therapeutic options of oncologic patients, allowing for more targeted and personalized chemotherapy regimens as well as for higher response rates

Social machines:A philosophical engineering

In Weaving the Web (2000), Berners-Lee defines Social Machines as biotechnologically hybrid Web-processes on the basis of which, “high-level activities, which have occurred just within one human’s brain, will occur among even larger more interconnected groups of people acting as if the shared a larger intuitive brain” (201–202). The analysis and design of Social Machines has already started attracting considerable attention both within the industry and academia. Web science, however, is still missing a clear definition of what a Social Machine is, which has in turn resulted in several calls for a “philosophical engineering” (Halpin 2013; Hendler & Berners-Lee 2010); Halpin et al. 2010). This paper is a first attempt to respond to this call, by combining contemporary philosophy of mind and cognitive science with epistemology. The idea of philosophical engineering implies that a sufficiently good conception of Social Machines should be of both theoretical and practical advantage. To demonstrate how the present approach can satisfy both objectives it will be used in order to address one of Wikipedia’s (the most famous Social Machine to date) most worrying concerns—i.e., the current and ongoing decline in the number of its active contributors (Halfacker et al. 2012)