Thermal imaging is a non-invasive alternative to PET-CT for measurement of brown adipose tissue activity in humans

Background Obesity and its metabolic consequences are a major cause of morbidity and mortality. Brown adipose tissue (BAT) utilises glucose and free fatty acids to produce heat, thereby increasing energy expenditure. Effective evaluation of human BAT stimulators is constrained by current standard BAT assessment methods as positron emission tomography-computed tomography (PET-CT) requires exposure to high doses of ionising radiation. Infrared thermography (IRT) is a potential non-invasive, safe alternative, although direct corroboration with PET-CT has not previously been established. Methods IRT and 18F-fluorodeoxyglucose (¹⁸F-FDG) PET-CT data from 8 healthy male participants subjected to water jacket cooling were directly compared. Thermal images (TIs) were geometrically transformed to overlay PET-CT-derived maximum intensity projection (MIP) images from each subject and the areas of greatest intensity of temperature and glucose-uptake within the supraclavicular regions compared. Relationships between supraclavicular temperatures from IRT (TSCR) and the maximum rate of glucose uptake (MR(gluc)) from PET-CT were determined. Results Glucose uptake on MR(gluc)MIP was positively correlated with change in TSCR relative to a reference region (r² = 0.721; p=0.008). Spatial overlap between areas of maximal MR(gluc)MIP and maximal TSCR was 29.5±5.1%. Prolonged cooling to 60 minutes was associated with further TSCR rise compared with cooling to 10 minutes. Conclusions The supraclavicular hotspot identified on IRT closely corresponds to the area of maximal uptake on PET-CT-derived MR(gluc)MIP images. Greater increases in relative TSCR were associated with raised glucose uptake. IRT should now be considered a suitable method for measuring BAT activation, especially in populations where PET-CT is not feasible, practical or repeatable

The oak or the reed: digital platforms and organisational resilience

Exogenous shocks are sudden changes faced by organisations, such as new regulations, natural disasters, and terrorist attacks, which negatively impact on their activities. When shocks occur, firms with a high level of resilience can continue their activities with little disruption. One way of becoming more resilient is by using digital platforms, as they provide organisations with affordances that make them more adaptable. For example, digital sales platforms allow organisations to market their product to more customers. On the other hand, digital platforms may reduce firms to establish organisational rigidity, as it may be difficult to change organisational processes embedded in digital platforms. Using technology affordance theory, this research uses case studies to explore the impact of digital platforms on organisational resilience during exogenous shocks

G93A-SOD1 C57BL/6 mice with dietary EPA at the symptomatic stage of the disease do not have a significantly different development of the disease compared to animals on the control diet.

<p>(A) Consumption of food is slightly increased when diet is enriched with EPA. (B) The body weight of mice was not affected as the disease evolves (C) Survival and (D) disease duration were not affected by dietary EPA. (E) The Rotarod and (F) The grip strength were not affected by dietary EPA.</p

Oral administration of EPA increases plasma EPA levels in G93A-SOD1 mice.

<p>Mice administered with either a single bolus dose of EPA (300 mg/kg, p.o.) or fed with an EPA enriched diet (300 mg/kg/day) for 7 days had higher levels of EPA and DHA in their plasma than mice fed on the control diet.</p

G93A-SOD1 C57BL/6 mice treated with EPA at the pre-symptomatic stage of the disease have an increase in vacuolization in the spinal cord.

<p>(A–B) Wild type littermates on the control diet have very sparse vacuoles within the spinal cord. (C–D) G93A-SOD1 mice on the control diet have vacuoles predominantly in the ventral horn. (E–F) Wild type littermates on the EPA diet have a slight increase in vacuoles within the spinal cord. (G–H) G93A-SOD1 mice on the EPA diet have a marked increase in vacuoles in the dorsal and ventral horn. (I–J) Quantitative analysis of vacuolisation in the spinal cord. Scale bar = 50 µm.</p

Microglia in G93A-SOD1 C57BL/6 mice treated with EPA at the pre-symptomatic stage of the disease have an elevated level of lipid oxidation.

<p>In the wild type littermates spinal cord (A–C) there is limited expression on 4-HHE. In the spinal cord of G93A-SOD1 mice, there was an increase in the level of 4-HHE expression (D–F). The treatment with EPA did not significantly alter the level of 4-HHE in the wild type mice (G–I), but significantly increased it in G93A-SOD1 mice (J–L) in comparison to the corresponding control group. Quantitative analysis of 4-HHE expression in the ventral horn of the spinal cord (M). Labelling shown is Iba1 (red), 4-HHE (green) and DAPI (blue). Scale bar = 100 µm.</p

Neuronal loss in G93A-SOD1 C57BL/6 mice treated with EPA at the pre-symptomatic stage of the disease is not affected by treatment.

<p>The G93A-SOD1 mice have significantly fewer neurons compared to the control wild type littermates, when the tissue is labelled with ChAT (motor neuron marker, red) or NeuN (general neuronal marker, green) (A–L). Nuclei are stained with DAPI (blue). No significant difference in cell number was observed between the EPA and control diet groups (M). Scale bar = 100 µm.</p

Astrocyte activation in G93A-SOD1 C57BL/6 mice treated with EPA at the pre-symptomatic stage of the disease is reduced by treatment.

<p>Some astrocytes can be observed in the wild-type littermate spinal cord (A–C). In the spinal cord of G93A-SOD1 mice, there is a significant increase in the number of astrocytes (D–F). The treatment with EPA did not significantly alter the number of astrocytes in wild type mice (G–I), but significantly reduced astrocytic activation in G93A-SOD1 mice (J–L) in comparison to the corresponding control group. Quantitative analysis of astrocytic cell number (M) and staining intensity (N) in the ventral horn of the mice spinal cord: GFAP (astrocytes, red), Nissl stain (neurons, green) and DAPI (nuclei, blue). Scale bar = 100 µm.</p

Increased EPA and DHA in the CNS of C57BL/6 mice treated with EPA at the pre-symptomatic stage of the disease.

<p>The level of DHA was significantly increased in both the brain (A) and spinal cord (B) in the presence of dietary EPA compared to the control diet in G93A-SOD1 mice.</p

G93A-SOD1 C57BL/6 mice treated with dietary EPA at the pre-symptomatic stage of ALS have an accelerated development of the disease compared to G93A-SOD1 mice on the control diet.

<p>(A) Consumption of food is increased in animals on the EPA enriched diet. (B) The body weight of mice with EPA diet decreases as the disease evolves. (C) Survival and (D) disease duration are both reduced with dietary EPA. (E) The Rotarod and (F) Hindlimb extension reflex are both affected by dietary EPA. (G) The rate at which the disease starts is not affected by dietary EPA. (H) The grip strength was not affected by dietary EPA.</p