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Peter Murray

Publications and source records attributed to Peter Murray.

5 recordsLinked to original sources
PubMed2006

IFN-gamma enhances production of nitric oxide from macrophages via a mechanism that depends on nucleotide oligomerization domain-2.

Pattern recognition receptors are central to the responsiveness of various eukaryotic cell types when they encounter pathogen-associated molecular patterns. IFN-gamma is a cytokine that is elevated in humans and other animals with bacterial infection and enhances the LPS-induced production of antibacterial mediators by macrophages. Mice lacking the pattern recognition receptor, TLR4, respond very poorly to stimulation by LPS, but administration of IFN-gamma has been described as restoring apparent sensitivity to this stimulatory ligand. In this study, we show that IFN-gamma primes murine macrophages stimulated by crude LPS preparations to produce the antibacterial mediator NO, a proportion of which is independent of TLRs 2 and 4. This response is lost in tlr4-/- IFN-gamma-primed murine macrophages when the LPS preparation is highly purified. NO is also induced if chemically synthesized muramyl dipeptide, an intermediate in the biosynthesis of peptidoglycan, is used to stimulate macrophages primed with IFN-gamma. This is absolutely dependent on the presence of a functional nucleotide oligomerization domain-2 (NOD-2) protein. IFN-gamma increases NOD-2 expression and dissociates this protein from the actin cytoskeleton within the cell. IFN-gamma priming of macrophages therefore reveals a key proinflammatory role for NOD-2. This study also shows that the effect of IFN-gamma in restoring inflammatory responses to gram-negative bacteria or bacterial products in mice with defective TLR4 signaling is likely to be due to a response to peptidoglycan, not LPS.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed2006

Thermal noise from optical coatings in gravitational wave detectors.

Gravitational waves are a prediction of Einstein's general theory of relativity. These waves are created by massive objects, like neutron stars or black holes, oscillating at speeds appreciable to the speed of light. The detectable effect on the Earth of these waves is extremely small, however, creating strains of the order of 10(-21). There are a number of basic physics experiments around the world designed to detect these waves by using interferometers with very long arms, up to 4 km in length. The next-generation interferometers are currently being designed, and the thermal noise in the mirrors will set the sensitivity over much of the usable bandwidth. Thermal noise arising from mechanical loss in the optical coatings put on the mirrors will be a significant source of noise. Achieving higher sensitivity through lower mechanical loss coatings, while preserving the crucial optical and thermal properties, is an area of active research right now.

Journal Article↗
PubMed2003

Applying quality management tools to medical photography services: a pilot project.

The Medical Photography Department at Peterborough Hospitals NHS Trust set up a pilot project to reduce the turnaround time of fundus fluorescein angiograms to the Ophthalmology Department. Quality management tools were used to analyse current photographic practices and develop more efficient methods of service delivery. The improved service to the Ophthalmology Department demonstrates the value of quality management in developing medical photography services at Peterborough Hospitals.

Ancillary Services, Hospital↗
PubMedDate not supplied

Effect of curing time and light curing systems on the surface hardness of compomers.

This study compared the Vickers hardness of the top and bottom surfaces of two compomers (Compoglass F and Dyract AP) polymerized for 20 and 40 seconds with two different light curing systems. Five samples for each group were prepared using Teflon molds (9x2 mm) and were light-cured either with a conventional halogen lamp (Optilux 501) or LED light (LEDemetron I) for 20 or 40 seconds. After curing, all the samples were stored in distilled water for 24 hours at 37 degrees C. The Vickers hardness measurements were obtained from the top and bottom surfaces of each sample. ANOVA, Scheffé and t-test were used to evaluate the statistical significance of the results. For the top and bottom surfaces, the light curing systems and curing times tested showed no statistical difference, except for Optilux 501, which used 20 seconds for both compomers (p<0.05). There was no significant difference in the microhardness of both surfaces of Compoglass F and Dyract AP cured for either 20 or 40 seconds using LEDemetron I. With Optilux 501, the microhardness of samples cured for 40 seconds was significantly higher than 20 seconds (p<0.05).

Compomers↗