No abstract

This report aims to facilitate the implementation of the Three Rs (replacement, reduction, and refinement) in the use of animal models or procedures involving sepsis and septic shock, an area where there is the potential of high levels of suffering for animals. The emphasis is on refinement because this has the greatest potential for immediate implementation. Specific welfare issues are identified and discussed, and practical measures are proposed to reduce animal use and suffering as well as reducing experimental variability and increasing translatability. The report is based on discussions and submissions from a nonregulatory expert working group consisting of veterinarians, animal technologists, and scientists with expert knowledge relevant to the field.

This review found that the survival of oncology patients admitted to the PICU with septic shock was not significantly different from control patients, and was significantly higher than previous reports. Aggressive management of these children is warranted as their long term prognosis may be much more favorable than originally thought.

Rheumatoid arthritis (RA) is a painful, chronic disorder and there is currently an unmet need for effective therapies that will benefit a wide range of patients. The research and development process for therapies and treatments currently involves in vivo studies, which have the potential to cause discomfort, pain or distress. This Working Group report focuses on identifying causes of suffering within commonly used mouse and rat ‘models’ of RA, describing practical refinements to help reduce suffering and improve welfare without compromising the scientific objectives. The report also discusses other, relevant topics including identifying and minimising sources of variation within in vivo RA studies, the potential to provide pain relief including analgesia, welfare assessment, humane endpoints, reporting standards and the potential to replace animals in RA research.

Single-stranded DNA sequences that are highly specific for a target ligand are called aptamers. While the incorporation of aptamer sequences into stem-loop molecular beacons has become an essential tool in optical biosensors, the design principles that determine the magnitude of binding affinity and its relationship to placement of the aptamer sequence in the stem-loop architecture are not well defined. By controlled placement of the aptamer along the loop region of the molecular beacon, it is observed that the binding affinity can be tuned over 4 orders of magnitude (1.3 nM – 203 μM) for the Huizenga and Szostak ATP DNA aptamer sequence. It is observed that the Kd is enhanced for the fully exposed sequence, with reduced binding affinity when the aptamer is part of the stem region of the beacon. Analysis of the ΔG values indicate a clear correlation between the aptamer hybridized length in the stem and its observed Kd. The use of a nanometal surface energy transfer probe method for monitoring ATP binding to the aptamer sequence allows the observation of negative cooperativity between the two ATP binding events. Maintenance of the high binding affinity of this ATP aptamer and the observation of two separate Kd’s for ATP binding indicate NSET as an effective, nonmanipulative, optical method for tracking biomolecular changes.