Dynamic neuroreceptor positron emission tomography in non-anesthetized rats using point source based motion correction: A feasibility study with [11C]ABP688

To prevent motion artifacts in small animal positron emission tomography (PET), animals are routinely scanned under anesthesia or physical restraint. Both may potentially alter metabolism and neurochemistry. This study investigates the feasibility of fully awake acquisition and subsequent absolute quantification of dynamic brain PET data via pharmacokinetic modelling in moving rats using the glutamate 5 receptor radioligand [11C]ABP688 and point source based motion correction. Five male rats underwent three dynamic [11C]ABP688 PET scans: two test-retest awake PET scans and one scan under anesthesia for comparison. Specific radioligand binding was determined via the simplified reference tissue model (reference: cerebellum) and outcome parameters BPND and R1 were evaluated in terms of stability and reproducibility. Test-retest measurements in awake animals gave reliable results with high correlations of BPND (y = 1.08 × -0.2, r = 0.99, p < 0.01) and an acceptable variability (mean over all investigated regions 15.7 ± 2.4%). Regional [11C]ABP688 BPNDs under awake and anesthetized conditions were comparable although in awake scans, absolute radioactive peak uptakes were lower and relative blood flow in terms of R1 was higher. Awake small animal PET with absolute quantification of neuroreceptor availability is technically feasible and reproducible thereby providing a suitable alternative whenever effects of anesthesia are undesirable, e.g. in sleep research.

A genetic variation in the adenosine A2A receptor gene contributes to variability in oscillatory alpha power in wake and sleep EEG and A1 adenosine receptor availability in the human brain

The EEG alpha rhythm (∼ 8-13 Hz) is one of the most salient human brain activity rhythms, modulated by the level of attention and vigilance and related to cerebral energy metabolism. Spectral power in the alpha range in wakefulness and sleep strongly varies among individuals based on genetic predisposition. Knowledge about the underlying genes is scarce, yet small studies indicated that the variant rs5751876 of the gene encoding A2A adenosine receptors (ADORA2A) may contribute to the inter-individual variation. The neuromodulator adenosine is directly linked to energy metabolism as product of adenosine tri-phosphate breakdown and acts as a sleep promoting molecule by activating A1 and A2A adenosine receptors. We performed sleep and positron emission tomography studies in 59 healthy carriers of different rs5751876 alleles, and quantified EEG oscillatory alpha power in wakefulness and sleep, as well as A1 adenosine receptor availability with 18F-CPFPX. Oscillatory alpha power was higher in homozygous C-allele carriers (n = 27, 11 females) compared to heterozygous and homozygous carriers of the T-allele (n(C/T) = 23, n(T/T) = 5, 13 females) (F(18,37) = 2.35, p = 0.014, Wilk's Λ = 0.487). Furthermore, a modulatory effect of ADORA2A genotype on A1 adenosine receptor binding potential was found across all considered brain regions (F(18,40) = 2.62, p = 0.006, Wilk's Λ = 0.459), which remained significant for circumscribed occipital region of calcarine fissures after correction for multiple comparisons. In female participants, a correlation between individual differences in oscillatory alpha power and A1 receptor availability was observed. In conclusion, we confirmed that a genetic variant of ADORA2A affects individual alpha power, while a direct modulatory effect via A1 adenosine receptors in females is suggested.

Correction of motion tracking errors for PET head rigid motion correction

Objective. In positron emission tomography (PET) rigid motion correction, erroneous tracking information translates into reduced quality in motion corrected reconstructions. We aim to improve the accuracy of the motion tracking data, to improve the quality of motion corrected reconstructions.Approach. We developed a method for correction of marker/skin displacement over the skull, for tracking methods which require multiple markers attached on the subject head. Additionally, we correct for small magnitude (∼1-2 mm) residual translation tracking errors that can still be present after other corrections. We performed [18F]FDG scans in awake mice (n= 8) and rats (n= 8), and dynamic [18F]SynVesT-1 scans in awake mice (n= 8). Head tracking was performed with the point source tracking method, attaching 3-4 radioactive fiducial markers on the animals' heads. List-mode even-by-event motion correction reconstruction was performed using tracking data obtained from the point source tracking method (MC), tracking data corrected for marker displacement (MC-DC), and tracking data with additional correction for residual translation tracking errors (MC-DCT). Image contrast, and the image enhancement metric (IEM, with MC as reference) were calculated in these 3 reconstructions.Main results. In mice [18F]FDG scans, the contrast increased on average 3% from MC to MC-DC (IEM: 1.01), and 5% from MC to MC-DCT (IEM: 1.02). For mice [18F]SynVesT-1 scans the contrast increased 6% from MC to MC-DC (IEM: 1.03), and 7% from MC to MC-DCT (IEM: 1.05). In rat [18F]FDG scans contrast increased 5% (IEM: 1.04), and 9% (IEM: 1.05), respectively.Significance. The methods presented here serve to correct motion tracking errors in PET brain scans, which translates into improved image quality in motion corrected reconstructions.

Effects of electroconvulsive therapy on cerebral A1 adenosine receptor availability: a PET study in patients suffering from treatment-resistant major depressive disorder

Introduction

Sleep deprivation and electroconvulsive therapy (ECT) effectively ameliorate symptoms in major depressive disorder (MDD). In rodents, both are associated with an enhancement of cerebral adenosine levels, which in turn likely influence adenosinergic receptor expression. The aim of the current study was to investigate cerebral A1 adenosine receptor (A1AR) availability in patients with MDD as a potential mediating factor of antidepressant effects of ECT using [18F]CPFPX and positron emission tomography (PET).

Methods

Regional A1AR availability was determined before and after a series of ECT applications (mean number ± SD 10.4 ± 1.2) in 14 subjects (4 males, mean age 49.5 ± 11.8 years). Clinical outcome, measured by neuropsychological testing, and ECT parameters were correlated with changes in A1AR availability.

Results

ECT had a strong antidepressive effect (p < 0.01) while on average cerebral A1AR availability remained unaltered between pre-and post-ECT conditions (F = 0.65, p = 0.42, mean difference ± SD 3.93% ± 22.7%). There was no correlation between changes in clinical outcome parameters and regional A1AR availability, although individual patients showed striking bidirectional alterations of up to 30-40% in A1AR availability after ECT. Solely, for the mean seizure quality index of the applied ECTs a significant association with changes in A1AR availability was found (rs = -0.6, p = 0.02).

Discussion

In the present study, therapeutically effective ECT treatment did not result in coherent changes of A1AR availability after a series of ECT treatments. These findings do not exclude a potential role for cerebral A1ARs in ECT, but shift attention to rather short-termed and adaptive mechanisms during ECT-related convulsive effects.

Associations between resting state brain activity and A1 adenosine receptor availability in the healthy brain: Effects of acute sleep deprivation

Introduction

Previous resting-state fMRI (Rs-fMRI) and positron emission tomography (PET) studies have shown that sleep deprivation (SD) affects both spontaneous brain activity and A1 adenosine receptor (A1AR) availability. Nevertheless, the hypothesis that the neuromodulatory adenosinergic system acts as regulator of the individual neuronal activity remains unexplored.

Methods

Therefore, fourteen young men underwent Rs-fMRI, A1AR PET scans, and neuropsychological tests after 52 h of SD and after 14 h of recovery sleep.

Results

Our findings suggested higher oscillations or regional homogeneity in multiple temporal and visual cortices, whereas decreased oscillations in cerebellum after sleep loss. At the same time, we found that connectivity strengths increased in sensorimotor areas and decreased in subcortical areas and cerebellum.

Discussion

Moreover, negative correlations between A1AR availability and rs-fMRI metrics of BOLD activity in the left superior/middle temporal gyrus and left postcentral gyrus of the human brain provide new insights into the molecular basis of neuronal responses induced by high homeostatic sleep pressure.

5f covalency from x-ray resonant Raman spectroscopy

X-ray resonant Raman spectroscopy (XRRS), a variant of resonant inelastic x-ray scattering, has been used to investigate the two prototype systems, UF₄and UO₂. Both are U5f²and each is an example of 5f localized, ionic behavior and 5f localized, covalent behavior, respectively. From the M₅XRRS measurements, the 5f band gap in each can be directly determined and, moreover, a clear and powerful sensitivity to 5f covalency emerges.

Designing for Growth and Development – A co-designed course for homeless people

Background

In many developed countries, homelessness remains an intractable challenge for intersectoral policies. People who are homeless struggle with a myriad of problems. They frequently experience stigmatisation and social marginalisation. Physical and mental health may be severely compromised, and it could be challenging to retain a sense of personal agency.

Objectives.

To co-design a personal and organisational development training course, in collaboration with clients and staff of a homeless service provider. To ensure that homeless individuals develop strategies and supports to help them navigate complex life circumstances. 6 three-hour workshops, informed by design-thinking. Each workshop session was co-designed (2 clients of a homeless charity, one staff member of staff, and two academics) in Ireland. Workshops followed the design cycle, starting with empathy exercises, then moved to define specific life challenges related to homelessness. Solution-focused ideation sessions followed. The team proceeded then to build a testable 'prototype'.

Results

The team jointly developed a high degree of creative confidence and shared responsibility for different sessions. The team developed a 'peer-support programme' as a tangible output. Academic team members gained deep insights into the lived experience of homelessness; client members deployed skills and experiences and gained renewed confidence in their abilities. The homeless charity proceeds with testing the 'peer-support' programme prototype.

Conclusions

We expect the Access and Life-Long learning programme at the university will offer the programme as a credit-bearing course. Its acceptability and usability will be tested.

Key messages

Homeless individuals can be meaningfully involved in designing services that empower them to navigate complex systems. Design thinking yields personal and organisational benefits.

PARE0033 I’M HERE BUT I’M NOT: A PHOTOVOICE STUDY OF THE LIVED EXPERIENCE OF SELF-MANAGING RHEUMATOID ARTHRITIS

Background:

Rheumatoid arthritis (RA) is a widespread chronic disease affecting about 1% of the population in the West. It is characterised by pain, fatigue and inflammation that can flare-up without warning. This makes the condition difficult to predict and manage. Bury (1982) introduced the concept of chronic illness as a disruptive experience to one’s self-identity. This is often an invisible part of managing the illness and taken for granted by others, such as family members, friends and health care professionals. Thus, there is a need to raise awareness of the patients’ lived experiences of self-managing this long-term chronic illness.

Objectives:

We aimed to collaborate with people with RA to (i) record and reflect the community’s strengths and concerns; (ii) raise awareness of the lived experience of self-managing RA (iii) spark a dialogue among key stakeholders around the self-management of RA.

Methods:

A purposeful sample of people with RA (n=12) was recruited. An innovative qualitative methodology, Photovoice, was used (Wang & Burris, 1997). A series of small group workshops took place. Participants were provided with cameras and appropriate training. They were asked to take photographs of the“challenges and solutions to living with RA” over approximately two weeks. Semi-structured interviews were conducted incorporating photo elicitation. As a group, the participants, a visual artist and researcher co-created a photo exhibition for the public.

Results:

Participants selected 32 photographs for the exhibition. They carried out a thematic analysis of the photos identifying four themes:

•I’m Here but I’m Not– this theme reflected feelings of alienation and social isolation.

•Medicine in all its forms –this theme captured attitudes towards medication and devices, as well as the creative ways people coped with RA.

•Visible illness– this concerned the recognition of RA. It captures the experience of RA as a “contested illness” and the challenge of gaining medical and cultural legitimacy.

•Mind yourself –this theme highlighted the value of self-care, often closely connected with the natural world and engagement with social activities.

Exhibitions were held at a community arts centre and a large central hospital in Dublin city. A plain language report was also collaboratively produced.

Conclusion:

This study shows how participatory methods can be used to explore the hidden experience of living with an invisible illness. This research design enabled participants to use photographs to reflect on their experiences and the meaning they intended to convey, thereby increasing trustworthiness of the findings through individual and group member checking. This approach extends beyond traditional written and verbal responses to share the worldview of participants. It demonstrates how to work with patients to create opportunities to improve awareness and spark dialogue among those who play a role in supporting the self-management of chronic illness. The integration of creative arts and participatory methods can have a positive impact for those involved in research and can enhance public engagement with research.

References:

[1]Bury, Michael (1982) Chronic Illness as Biographical Disruption. Sociology of Health & Illness. 4. 167-82.

[2]Wang, C., & Burris, M. A. (1997). Photovoice: Concept, Methodology, and Use for Participatory Needs Assessment.Health Education & Behavior,24(3), 369–387.

Acknowledgments:

Funding is awarded from the UCD Wellcome Trust Institutional Strategic Support Fund as part of a Medical Humanities and Social Science Collaboration Scheme (ref 204844/Z/16/Z).

As part of a Patient and Public Involvement (PPI) strand, a Research Advisory Group composed of people living with RA was supported the design and execution of this project.

Disclosure of Interests:

None declared

A versatile Johansson-type tender x-ray emission spectrometer

We present a high energy resolution x-ray spectrometer for the tender x-ray regime (1.6-5.0 keV) that was designed and operated at Stanford Synchrotron Radiation Lightsource. The instrument is developed on a Rowland geometry (500 mm of radius) using cylindrically bent Johansson analyzers and a position sensitive detector. By placing the sample inside the Rowland circle, the spectrometer operates in an energy-dispersive mode with a subnatural line-width energy resolution (∼0.32 eV at 2400 eV), even when an extended incident x-ray beam is used across a wide range of diffraction angles (∼30° to 65°). The spectrometer is enclosed in a vacuum chamber, and a sample chamber with independent ambient conditions is introduced to enable a versatile and fast-access sample environment (e.g., solid/gas/liquid samples, in situ cells, and radioactive materials). The design, capabilities, and performance are presented and discussed.

Image-Derived Input Functions for Quantification of A1 Adenosine Receptors Availability in Mice Brains Using PET and [18F]CPFPX

Purpose

In vivo imaging for the A₁ adenosine receptors (A₁ARs) with positron emission tomography (PET) using 8-cyclopentyl-3-(3-[¹⁸F]fluoropropyl)-1-propylxan- thine ([¹⁸F]CPFPX) has become an important tool for studying physiological processes quantitatively in mice. However, the measurement of arterial input functions (AIFs) on mice is a method with restricted applicability because of the small total blood volume and the related difficulties in withdrawing blood. Therefore, the aim of this study was to extract an appropriate [¹⁸F]CPFPX image-derived input function (IDIF) from dynamic PET images of mice.

Procedures

In this study, five mice were scanned with [¹⁸F]CPFPX for 60 min. Arterial blood samples (n = 7 per animal) were collected from the femoral artery and corrected for metabolites. To generate IDIFs, three different approaches were selected: (A) volume of interest (VOI) placed over the heart (cube, 10 mm); (B) VOI set over abdominal vena cava/aorta region with a cuboid (5 × 5 × 15 mm); and (C) with 1 × 1 × 1 mm voxels on five consecutive slices. A calculated scaling factor (α) was used to correct for partial volume effect; the method of obtaining the total metabolite correction of [¹⁸F]CPFPX for IDIFs was developed. Three IDIFs were validated by comparison with AIF. Validation included the following: visual performance; computing area under the curve (AUC) ratios (IDIF/AIF) of whole-blood curves and parent curves; and the mean distribution volume (V_T) ratios (IDIF/AIF) of A₁ARs calculated by Logan plot and two-tissue compartment model.

Results

Compared with the AIF, the IDIF with VOI over heart showed the best performance among the three IDIFs after scaling by 1.77 (α) in terms of visual analysis, AUC ratios (IDIF/AIF; whole-blood AUC ratio, 1.03 ± 0.06; parent curve AUC ratio, 1.01 ± 0.10) and V_T ratios (IDIF/AIF; Logan V_T ratio, 1.00 ± 0.17; two-tissue compartment model V_T ratio, 1.00 ± 0.13) evaluation. The A₁ARs distribution of average parametric images was in good accordance to autoradiography of the mouse brain.

Conclusion

The proposed study provides evidence that IDIF with VOI over heart can replace AIF effectively for quantification of A₁ARs using PET and [¹⁸F]CPFPX in mice brains.

Impact of acute sleep deprivation on dynamic functional connectivity states

Sleep deprivation (SD) could amplify the temporal fluctuation of spontaneous brain activities that reflect different arousal levels using a dynamic functional connectivity (dFC) approach. Therefore, we intended to evaluate the test–retest reliability of dFC characteristics during rested wakefulness (RW), and to explore how the properties of these dynamic connectivity states were affected by extended durations of acute sleep loss (28/52 hr). We acquired resting‐state fMRI and neuropsychological datasets in two independent studies: (a) twice during RW and once after 28 hr of SD (n = 15) and (b) after 52 hr of SD and after 14 hr of recovery sleep (RS; n = 14). Sliding‐window correlations approach was applied to estimate their covariance matrices and corresponding three connectivity states were generated. The test–retest reliability of dFC properties demonstrated mean dwell time and fraction of connectivity states were reliable. After SD, the mean dwell time of a specific state, featured by strong subcortical–cortical anticorrelations, was significantly increased. Conversely, another globally hypoconnected state was significantly decreased. Subjective sleepiness and objective performances were separately positive and negative correlated with the increased and decreased state. Two brain connectivity states and their alterations might be sufficiently sensitive to reflect changes in the dynamics of brain mental activities after sleep loss.

"We're really not ready for this": A qualitative exploration of community pharmacy personnel's perspectives on the pharmaceutical care of older people with sensory impairment

Background

In most developed countries there is an increasing ageing population living in the community with long-term conditions and sensory impairment (sight; hearing; dual impairment). Community pharmacy personnel are key providers of pharmaceutical care to this patient population.

Objective

This study explored community pharmacy personnel's experiences with providing pharmaceutical care for older people with sensory impairment.

Methods

Semi-structured telephone interviews were conducted with community pharmacy personnel across Scotland between 2015 and 2016.

Results

Thirty interviews were completed with community pharmacists (n = 17) and other pharmacy personnel (n = 13). Two overarching themes emerged: safety and communication. Interviewees reported patients' reluctance to disclose their impairment “patients are very good at hiding it” and had considerable safety concerns “it's a fear that they're going to take too much … accidentally taking the same medicine twice”. Difficulties in communication were cited “no matter what you do or how you label things, leaflets and telling people, things can go wrong”. Additionally, interviewees identified training needs to increase their disability awareness and to identify strategies to provide safe and reliable pharmaceutical care to this vulnerable group “We don't specifically have anything in place to deal with anyone with impairments of that kind”.

Conclusions

This is the first in-depth exploration of providing pharmaceutical care to older people with sensory impairment from the perspective of community pharmacy personnel. Strategies are needed to encourage older people to disclose their sensory impairment. Education and training are also needed to optimise the provision of pharmaceutical care to this vulnerable population.

Towards characterization of photo-excited electron transfer and catalysis in natural and artificial systems using XFELs

The ultra-bright femtosecond X-ray pulses provided by X-ray Free Electron Lasers (XFELs) open capabilities for studying the structure and dynamics of a wide variety of biological and inorganic systems beyond what is possible at synchrotron sources. Although the structure and chemistry at the catalytic sites have been studied intensively in both biological and inorganic systems, a full understanding of the atomic-scale chemistry requires new approaches beyond the steady state X-ray crystallography and X-ray spectroscopy at cryogenic temperatures. Following the dynamic changes in the geometric and electronic structure at ambient conditions, while overcoming X-ray damage to the redox active catalytic center, is key for deriving reaction mechanisms. Such studies become possible by using the intense and ultra-short femtosecond X-ray pulses from an XFEL, where sample is probed before it is damaged. We have developed methodology for simultaneously collecting X-ray diffraction data and X-ray emission spectra, using an energy dispersive spectrometer, at ambient conditions, and used this approach to study the room temperature structure and intermediate states of the photosynthetic water oxidizing metallo-protein, photosystem II. Moreover, we have also used this setup to simultaneously collect the X-ray emission spectra from multiple metals to follow the ultrafast dynamics of light-induced charge transfer between multiple metal sites. A Mn-Ti containing system was studied at an XFEL to demonstrate the efficacy and potential of this method.

Development of the cancer-related loneliness assessment tool: Using the findings of a qualitative analysis to generate questionnaire items

The aim of this research was to develop a tool to identify and assess the qualities of cancer-related loneliness in adult cancer survivors who have completed treatment. In addition to reporting the development of the tool, we explicate the process of using the findings of a qualitative analysis to generate questionnaire items, as currently little guidance exists on this topic. The findings of our qualitative research exploring the experience of loneliness in adult cancer survivors who had completed treatment, together with the findings of our concept analysis of loneliness, were used to develop an assessment tool for cancer-related loneliness following treatment completion. Cognitive testing was undertaken to assess fidelity of comprehension and feasibility in administration. The Cancer-Related Loneliness Assessment Tool is a 10-item self-report questionnaire capturing the essential elements of cancer-related loneliness following treatment completion. Experts believed the questionnaire to be face-valid and usable in clinical practice, and preliminary cognitive testing indicated that the items generate the information intended and individuals have little trouble completing the tool. Following further development work, the tool could be employed to identify cancer-related loneliness following treatment completion. It could also aid with the development/adaptation and evaluation of person-centred interventions to address such loneliness.

Neurotransmitter receptor availability in the rat brain is constant in a 24 hour-period

Wakefulness and sleep are fundamental characteristics of the brain. We, therefore, hypothesized that transmitter systems contribute to their regulation and will exhibit circadian alterations. We assessed the concentration of various neurotransmitter receptors and transporters including adenosinergic (A₁AR, A_2AAR, and ENT1), dopaminergic (D₁R, D₂R, and DAT), and serotonergic (5-HT_2AR) target proteins. Adult male Sprague Dawley rats were used and maintained in a 12 h light: 12 h dark cycle (lights on from 07:00 h to 19:00 h). We measured receptor and transporter concentrations in different brain regions, including caudate putamen, basal forebrain, and cortex in 4 hour-intervals over a 24 hour-period using quantitative in vitro autoradiography. Investigated receptors and transporters showed no fluctuations in any of the analyzed regions using one-way ANOVA. Only in the horizontal diagonal band of Broca, the difference of A₁AR concentration between light and dark phases (t-test) as well as the cosinor analysis of the 24 hour-course were significant, suggesting that this region underlies receptor fluctuations. Our findings suggest that the availability of the investigated neurotransmitter receptors and transporters does not undergo changes in a 24 hour-period. While there are reports on changes in adenosine and dopamine receptors during sleep deprivation, we found no changes in the investigated adenosine, dopamine, and serotonin receptors during regular and undisturbed day-night cycles.

Circadian variation of metabotropic glutamate receptor 5 availability in the rat brain

The metabotrophic subtype 5 glutamate receptor (mGluR5) plays a critical role in synaptic plasticity besides its involvement in numerous neurological disorders, such as depression. As mGluR5 availability in humans is altered in sleep deprivation, we hypothesized that mGluR5 availability underlies a circadian variation. To investigate whether mGluR5 underlies potential circadian changes we measured its density in a randomized fashion at six different daytimes in 11 adult Sprague-Dawley rats. mGluR5 density was quantified by positron emission tomography (PET) using the radioactive ligand [¹¹ C]ABP688. [¹¹ C]ABP688 uptake was quantified in nine regions of interest with a reference tissue model. Significant differences in the binding potential (BP_ND ) and therefore mGluR5 availability between the different circadian times were found in cortex, cingulate cortex, amygdala, caudate putamen and nucleus accumbens. Further post-hoc statistical analysis (Tukey-Kramer test) of the different time-points revealed significant changes in BP_ND between 07:00 hours (start of light-on phase) and 15:00 hours (last time-point of the light-on phase) in the caudate putamen. This study shows that mGluR5 availability is increased during the light-on, or sleep phase, of rodents by approximately 10%. Given that altered mGluR5 densities play a role in psychiatric disorders, further investigation is warranted to evaluate their circadian involvement in mood changes in humans.

Prevalence of Glucosamine and Omega-3 Fatty Acid Use and Characteristics of Users among Mid-Age Women: Analysis of a Nationally Representative Sample of 10,638 Women

BACKGROUND

There has been a dramatic increase in the use of dietary supplements over the last few decades and both omega-3 fatty acids and glucosamine are two of the best-selling dietary supplements in many countries. An understanding of omega-3 fatty acids and glucosamine consumption is of significance to health care providers and for future health promotion activities.

METHODS

This research involved analysis of data collected from a nationally-representative sample of Australian women as part of the Australian Longitudinal Study on Women's Health (ALSWH). Participants' use of omega-3 fatty acids (FA), glucosamine, their demographics, health status and health care utilisation were measured. Analysis included logistic regression modelling.

RESULTS

Of the 10,638 women in the study, 26.8% reported use of omega-3 FA and 15.9% glucosamine. Women with osteoarthritis (OR=2.529; 95% CI: 2.190, 2.921), other arthritis (OR= 1.618; 95% CI: 1.375, 1.905), and joint pain (OR= 2.699; 95% CI: 2.305, 3.160) were more likely to use glucosamine (all p<0.001). In contrast, those with diabetes (OR= 0.471; 95% CI: 0.343, 0.646) or depression (OR= 0.764; 95% CI: 0.657, 0.887) were less likely to use glucosamine (both p<0.001). Women with osteoarthritis (OR=1.481; 95% CI: 1.297, 1.691) and joint pain (OR= 1.456; 95% CI: 1.306, 1.622) were more likely to use omega-3 FA (all p<0.001).

CONCLUSIONS

Substantial prevalence rates for use of glucosamine and omega-3 FA amongst mid-aged women highlights the need for health practitioners and policymakers to be mindful of the possible significant role of such supplement use as part of patient health-seeking behaviours.

Reproducibility of non-invasive a1 adenosine receptor quantification in the rat brain using [(18)F]CPFPX and positron emission tomography

PURPOSE

The A1AR antagonist 8-cyclopentyl-3-(3-fluoropropyl)-1-propylxanthine ([(18)F]CPFPX) has recently been shown to be a suitable radiotracer for quantitative in vivo imaging of the A1 adenosine receptor (A1AR) in rats. The present study evaluates the reproducibility of non-invasive longitudinal A1AR studies with [(18)F]CPFPX and a dedicated small animal positron emission tomography (PET) scanner.

PROCEDURES

Twelve male Sprague Dawley rats underwent four repeated dynamic PET scans with a bolus injection of [(18)F]CPFPX. A1AR availability was determined by different non-invasive approaches including simplified and multilinear reference tissue (olfactory bulb)-based models and graphical methods. The outcome parameter binding potential (BP) was evaluated in terms of variability and reproducibility.

RESULTS

Repeated estimations of [(18)F]CPFPX BP ND gave reliable results with acceptable variability (mean 12 %) and reproducibility (intraclass correlation coefficients raging from 0.57 to 0.68) in cortical and subcortical regions of the rat brain. With regard to kinetic models, test-retest stability of the simplified reference-tissue model (SRTM) was superior to multilinear and graphical approaches.

CONCLUSIONS

Non-invasive quantification of A1AR density in the rat brain is reproducible and reliable with [(18)F]CPFPX PET and allows longitudinal designs of in vivo imaging studies in rodents.

Chronic sleep restriction induces long-lasting changes in adenosine and noradrenaline receptor density in the rat brain

Although chronic sleep restriction frequently produces long-lasting behavioural and physiological impairments in humans, the underlying neural mechanisms are unknown. Here we used a rat model of chronic sleep restriction to investigate the role of brain adenosine and noradrenaline systems, known to regulate sleep and wakefulness, respectively. The density of adenosine A1 and A2a receptors and β-adrenergic receptors before, during and following 5 days of sleep restriction was assessed with autoradiography. Rats (n = 48) were sleep-deprived for 18 h day(-1) for 5 consecutive days (SR1-SR5), followed by 3 unrestricted recovery sleep days (R1-R3). Brains were collected at the beginning of the light period, which was immediately after the end of sleep deprivation on sleep restriction days. Chronic sleep restriction increased adenosine A1 receptor density significantly in nine of the 13 brain areas analysed with elevations also observed on R3 (+18 to +32%). In contrast, chronic sleep restriction reduced adenosine A2a receptor density significantly in one of the three brain areas analysed (olfactory tubercle which declined 26-31% from SR1 to R1). A decrease in β-adrenergic receptors density was seen in substantia innominata and ventral pallidum which remained reduced on R3, but no changes were found in the anterior cingulate cortex. These data suggest that chronic sleep restriction can induce long-term changes in the brain adenosine and noradrenaline receptors, which may underlie the long-lasting neurocognitive impairments observed in chronic sleep restriction.

Association of adenosine receptor gene polymorphisms and in vivo adenosine A1 receptor binding in the human brain

Adenosine A1 receptors (A1ARs) and the interacting adenosine A2A receptors are implicated in neurological and psychiatric disorders. Variants within the corresponding genes ADORA1 and ADORA2A were shown associated with pathophysiologic alterations, particularly increased anxiety. It is unknown so far, if these variants might modulate the A1AR distribution and availability in different brain regions. In this pilot study, the influence of ADORA1 and ADORA2A variants on in vivo A1AR binding was assessed with the A1AR-selective positron emission tomography (PET) radioligand [(18)F]CPFPX in brains of healthy humans. Twenty-eight normal control subjects underwent PET procedures to calculate the binding potential BPND of [(18)F]CPFPX in cerebral regions and to assess ADORA1 and ADORA2A single nucleotide polymorphism (SNP) effects on regional BPND data. Our results revealed SNPs of both genes associated with [(18)F]CPFPX binding to the A1AR. The strongest effects that withstood even Bonferroni correction of multiple SNP testing were found in non-smoking subjects (N=22) for ADORA2A SNPs rs2236624 and rs5751876 (corr. Pall<0.05). SNP alleles previously identified at risk for increased anxiety like the rs5751876 T-allele corresponded to consistently higher A1AR availability in all brain regions. Our data indicate for the first time that variation of A1AR availability was associated with ADORA SNPs. The finding of increased A1AR availability in regions of the fear network, particularly in ADORA2A risk allele carriers, strongly warrants evaluation and replication in further studies including individuals with increased anxiety.

[¹⁸F]Altanserin and small animal PET: impact of multidrug efflux transporters on ligand brain uptake and subsequent quantification of 5-HT₂A receptor densities in the rat brain

INTRODUCTION

The selective 5-hydroxytryptamine type 2a receptor (5-HT(2A)R) radiotracer [(18)F]altanserin is a promising ligand for in vivo brain imaging in rodents. However, [(18)F]altanserin is a substrate of P-glycoprotein (P-gp) in rats. Its applicability might therefore be constrained by both a differential expression of P-gp under pathological conditions, e.g. epilepsy, and its relatively low cerebral uptake. The aim of the present study was therefore twofold: (i) to investigate whether inhibition of multidrug transporters (MDT) is suitable to enhance the cerebral uptake of [(18)F]altanserin in vivo and (ii) to test different pharmacokinetic, particularly reference tissue-based models for exact quantification of 5-HT(2A)R densities in the rat brain.

METHODS

Eighteen Sprague-Dawley rats, either treated with the MDT inhibitor cyclosporine A (CsA, 50 mg/kg, n=8) or vehicle (n=10) underwent 180-min PET scans with arterial blood sampling. Kinetic analyses of tissue time-activity curves (TACs) were performed to validate invasive and non-invasive pharmacokinetic models.

RESULTS

CsA application lead to a two- to threefold increase of [(18)F]altanserin uptake in different brain regions and showed a trend toward higher binding potentials (BP(ND)) of the radioligand.

CONCLUSIONS

MDT inhibition led to an increased cerebral uptake of [(18)F]altanserin but did not improve the reliability of BP(ND) as a non-invasive estimate of 5-HT(2A)R. This finding is most probable caused by the heterogeneous distribution of P-gp in the rat brain and its incomplete blockade in the reference region (cerebellum). Differential MDT expressions in experimental animal models or pathological conditions are therefore likely to influence the applicability of imaging protocols and have to be carefully evaluated.

In vivo kinetic and steady-state quantification of 18F-CPFPX binding to rat cerebral A1 adenosine receptors: validation by displacement and autoradiographic experiments

In vivo imaging of the A1 adenosine receptor (A1AR) using (18)F-8-cyclopentyl-3-(3-fluoropropyl)-1-propylxanthine ((18)F-CPFPX) and PET has become an important tool for studying physiologic and pathologic states of the human brain. However, dedicated experimental settings for small-animal studies are still lacking. The aim of the present study was therefore to develop and evaluate suitable pharmacokinetic models for the quantification of the cerebral A1AR in high-resolution PET.

METHODS

On a dedicated animal PET scanner, 15 rats underwent (18)F-CPFPX PET scans of 120-min duration. In all animals, arterial blood samples were drawn and corrected for metabolites. The radioligand was injected either as a bolus or as a bolus plus constant infusion. For the definition of unspecific binding, the A1AR selective antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) was applied. After PET, the brains of 9 animals were dissected and in vitro saturation binding was performed using high-resolution (3)H-DPCPX autoradiography.

RESULTS

The kinetics of (18)F-CPFPX were well described by either compartmental or noncompartmental models based on arterial input function. The resulting distribution volume ratio correlated with a low bias toward identity with the binding potential derived from a reference region (olfactory bulb) approach. Furthermore, PET quantification correlated significantly with autoradiographic in vitro data. Blockade of the A1AR with DPCPX identified specific binding of about 45% in the reference region olfactory bulb.

CONCLUSION

The present study provides evidence that (18)F-CPFPX PET based on a reference tissue approach can be performed quantitatively in rodents in selected applications. Specific binding in the reference region needs careful consideration for quantitative investigations.

[Current practice of tumour endoscopy in German ENT-clinics]

BACKGROUND

Second primary carcinomas (SPC) essentially influence therapy and the outcome in head and neck cancer. This study presents the current status of tumour endoscopy in German ENT-clinics.

MATERIAL AND METHODS

A standardised questionnaire regarding indication, time of event, examined anatomical region and technique of tumour endoscopy was compiled, sent to all German ENT-clinics (n=159) and subsequently analysed.

RESULTS

In 94-100% of the clinics, tumour endoscopy is being conducted when primary carcinoma lies within oral cavity, pharynx, larynx or is a CUP-syndrome. In 80%, 2-stage surgical procedure is preferred. Nasal cavity and tracheobronchial system (47%, 74%) are often not included in the examination. When primary cancer is seen, in 7% of the clinics a standardised biopsy of unsuspicious anatomic areas is conducted. In CUP-syndrome, unsuspicious surfaces within the pharynx do not undergo routine biopsy in 10-20% of the clinics. In tracheobronchoscopy (63.0%) and esophagoscopy (93.3%) rigid scopes are mainly used. 65% of the clinics conduct endoscopy as follow-up care.

CONCLUSION

Practice of tumour endoscopy in German ENT-clinics is widespread but does not follow standardised mechanisms. Current international literature shows that there is no common consensus on value and techniques of tumour endoscopy, however, due to highly developed radiological diagnostics, risks of rigid endoscopies and unknown incidence of second primary tumours it is discussed more and more negative. To establish future guidelines, controlled studies or analysis of large populations seem to be necessary.

Abstract P1-07-16: Liver derived epithelial cells as source of false positive circulating tumor cells in early breast cancer

The MAINTRAC technique as introduced by our coworkers from Jena (RBC lysis, fluorometric detection and analysis on Olympius ScanR) detects more circulating epithelial cells than techniques using enrichment. Also cells with a low EPCAM expression are detected and not only the typical cells with bright expression found after immunomagnetic enrichment. The relative cheapness and reproducibility allows frequent monitoring during and after therapy Using 3 colour detection (EPCAMfitc, DAPI, Vimentin PE) living and dead circulating epithelial cells in EMT, or cells in EMT with stemcell markers (EPCAMfitc, Vimentin-PE, CD44PacBlue) can be detected. In early breast cancer (n = 135) cells can be found in 60% of patients and in 40% higher cell counts (&gt;100 ml are detectable. A control population(n = 100) showed low numbers in 98% (e.g (&lt;100 CECin 1 ml blood). Expression of the mesenchymal marker (vimentin) ranges between 10 and 40% with different expression. CD44 shows also a wide range of expression. Two main cell types can be distinguished: type 1 shows generalized but weaker expression patterns and a second type with very bright dotted expression. The clinical relevance of these subsets is not known and their behavior under therapy has not been analysed in depth yet. In advanced breast cancers high cell counts were detectable in most patients with a less agressive disease course. In the rapidly progressing unfavorable subtypes (TN and Her2+. HRneg) less or none cells were found. During crossvalidation in non cancer patients we found high cell numbers in several forms of liver affections (n = 108). The expression patterns of markers on these cells were not differing from those in cancer patients. So this same cell type merging EMT, stemcell an hypoxic stress markers is detectable in advanced and early breast cancer (n = 40) and in benign disease. These cells disappear or decrease after response to chemo or anti-hormonal therapy in cancer or antioxidant therapy in NAFLD. We believe that the evasion of these cells is driven by the same force in cancer as in non cancer conditions. We suggest that this are the wellknown hypoxic and hyperacidic conditions causing epithelial mesenchymal transition. Cancer cell hijack this functions occurring normally under these conditions to survive and to facilitate evasion. More comprehensive analysis (four colour analysis on the AMNIS Flowsight) is needed and should show differences in expression patterns of liver derived epithelial cells (LDEC) and real tumor derived epithelial cells (TDEC). Further clarification of these phenomena should give new insights of the biological events in early disease and the possibilities and reliability of “fluid biopsy”.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-07-16.

Sleep deprivation increases cerebral serotonin 2A receptor binding in humans

STUDY OBJECTIVES

Serotonin and its cerebral receptors play an important role in sleep-wake regulation. The aim of the current study is to investigate the effect of 24-h total sleep deprivation on the apparent serotonin 2A receptor (5-HT(2A)R) binding capacity in the human brain to test the hypothesis that sleep deprivation induces global molecular alterations in the cortical serotonergic receptor system.

DESIGN

Volunteers were tested twice with the subtype-selective radiotracer [(18)F]altanserin and positron emission tomography (PET) for imaging of 5-HT(2A)Rs at baseline and after 24 h of sleep deprivation. [(18)F]Altanserin binding potentials were analyzed in 13 neocortical regions of interest. The efficacy of sleep deprivation was assessed by questionnaires, waking electroencephalography, and cognitive performance measurements.

SETTING

Sleep laboratory and neuroimaging center.

PATIENTS OR PARTICIPANTS

Eighteen healthy volunteers.

INTERVENTIONS

Sleep deprivation.

MEASUREMENTS AND RESULTS

A total of 24 hours of sleep deprivation led to a 9.6% increase of [(18)F]altanserin binding on neocortical 5-HT(2A) receptors. Significant region-specific increases were found in the medial inferior frontal gyrus, insula, and anterior cingulate, parietal, sensomotoric, and ventrolateral prefrontal cortices.

CONCLUSIONS

This study demonstrates that a single night of total sleep deprivation causes significant increases of 5-HT(2A)R binding potentials in a variety of cortical regions although the increase declines as sleep deprivation continued. It provides in vivo evidence that total sleep deprivation induces adaptive processes in the serotonergic system of the human brain.

Normative database of the serotonergic system in healthy subjects using multi-tracer PET

The highly diverse serotonergic system with at least 16 different receptor subtypes is implicated in the pathophysiology of most neuropsychiatric disorders including affective and anxiety disorders, obsessive compulsive disorder, post-traumatic stress disorder, eating disorders, sleep disturbance, attention deficit/hyperactivity disorder, drug addiction, suicidal behavior, schizophrenia, Alzheimer, etc. Alterations of the interplay between various pre- and postsynaptic receptor subtypes might be involved in the pathogenesis of these disorders. However, there is a lack of comprehensive in vivo values using standardized procedures. In the current PET study we quantified 3 receptor subtypes, including the major inhibitory (5-HT(1A) and 5-HT(1B)) and excitatory (5-HT(2A)) receptors, and the transporter (5-HTT) in the brain of healthy human subjects to provide a database of standard values. PET scans were performed on 95 healthy subjects (age=28.0 ± 6.9 years; 59% males) using the selective radioligands [carbonyl-(11)C]WAY-100635, [(11)C]P943, [(18)F]altanserin and [(11)C]DASB, respectively. A standard template in MNI stereotactic space served for region of interest delineation. This template follows two anatomical parcellation schemes: 1) Brodmann areas including 41 regions and 2) AAL (automated anatomical labeling) including 52 regions. Standard values (mean, SD, and range) for each receptor and region are presented. Mean cortical and subcortical binding potential (BP) values were in good agreement with previously published human in vivo and post-mortem data. By means of linear equations, PET binding potentials were translated to post-mortem binding (provided in pmol/g), yielding 5.89 pmol/g (5-HT(1A)), 23.5 pmol/g (5-HT(1B)), 31.44 pmol/g (5-HT(2A)), and 11.33 pmol/g (5-HTT) being equivalent to the BP of 1, respectively. Furthermore, we computed individual voxel-wise maps with BP values and generated average tracer-specific whole-brain binding maps. This knowledge might improve our interpretation of the alterations taking place in the serotonergic system during neuropsychiatric disorders.

Overcoming perceived barriers to employment among people with arthritis

Work disability is a major problem for people with arthritis. The INTO WORK Personal Development (IWPD) programme aims to prevent work disability by addressing the internal and external barriers faced by people with arthritis seeking to fulfil their employment potential. The effectiveness of the programme was examined in a pretest-post-test study with an intervention group (n = 37) and a comparison control group (n = 42). Data were collected through self-administered questionnaires and focus groups. Significant decreases on anxiety (p = .0002), depression (p = .009) and negative mood (p = .029), and significant improvements on positive mood (p = .011), self-esteem (p = .002) and satisfaction with life (p = .010) were found for the intervention group only. The IWPD programme appears to promote self-determination, psychological well-being and strategies for overcoming perceived barriers to employment among people with arthritis.

[Sialendoscopy--learning curve and nation-wide survey in German ENT-departments]

BACKGROUND

Sialendoscopy is an established, minimal-invasive technique to diagnose and treat obstructive diseases of major salivary glands. Knowledge on learning curve and distribution in Germany is limited. MATERIAL UND METHODS: An 11 item questionnaire on Sialendoscopy was sent to all 159 German ent-hospitals. To determine the learning curve, all patients that underwent sialendoscopy during a 1-year-period after invention of sialendoscopy in our department were prospectively followed and evaluated.

RESULTS

Sialendoscopy is currently performed in a minority (24%) of ent-departments in Germany. Denial was justified by technical problems, a lack of cost-benefit and small number of patients in descending order. A significant reduction of intervention time (61.0 ± 32.7 min to 43.2 ± 33.6 min, p=0.013) and less frequent aborted operations were noted after comparison of the first vs. the second half amount of interventions as indicators of a learning curve. Complications were not found to be significantly raised in the first half of interventions.

CONCLUSION

The fact that sialendoscopy is provided in only a minority of ent-departments will in the future most likely be overcome by technical improvements. A learning curve has to be anticipated.

Efficacy control of therapy using circulating epithelial tumor cells (CETC) as "liquid biopsy": trastuzumab in HER2/neu-positive breast carcinoma

PURPOSE

The majority of targeted personalized cancer therapies are effective only in part of the patients, and most of these drugs are excessively expensive. Therefore, methods are urgently required, which reveal already early during treatment, whether the therapy is effective. In the present report, monitoring of circulating epithelial tumor cells (CETC) was used as a timely control of trastuzumab therapy in patients with HER2/neu-positive breast cancer.

METHODS

Seventy-nine sequential HER2/neu-positive breast cancer patients, 35 without trastuzumab, and 36 treated with 1 year of trastuzumab treatment were included. CETC from unseparated white blood cells stained with FITC-anti-EpCAM were analyzed repeatedly during chemotherapy and between 2 and 10 times during 1 year of maintenance treatment or observation.

RESULTS

Patients treated with trastuzumab had a better relapse-free survival than patients without trastuzumab treatment during the first 2-4 years of follow-up. Decrease in numbers or no change versus highly variable numbers or increase (fivefold or more) allowed to discriminate highly significantly and clearly (P < 0.0001, hazard ratio 5.5) between patients with a low or high risk of relapse. An increase in CETC was accompanied by an increasing portion of cells containing a very high number of HER2/neu gene amplificates.

CONCLUSIONS

Analysis of the behavior of CETC can, in the future, contribute to evaluate the efficacy of targeted therapy early during the course of the disease, sparing patients unnecessary treatment but also to reduce the costs for the health system and to downsize the extent and length of clinical studies.

Efficacy control of therapy using circulating epithelial tumor cells (CETC) as "liquid biopsy": trastuzumab in HER2/neu-positive breast carcinoma

Purpose

The majority of targeted personalized cancer therapies are effective only in part of the patients, and most of these drugs are excessively expensive. Therefore, methods are urgently required, which reveal already early during treatment, whether the therapy is effective. In the present report, monitoring of circulating epithelial tumor cells (CETC) was used as a timely control of trastuzumab therapy in patients with HER2/neu-positive breast cancer.

Methods

Seventy-nine sequential HER2/neu-positive breast cancer patients, 35 without trastuzumab, and 36 treated with 1 year of trastuzumab treatment were included. CETC from unseparated white blood cells stained with FITC-anti-EpCAM were analyzed repeatedly during chemotherapy and between 2 and 10 times during 1 year of maintenance treatment or observation.

Results

Patients treated with trastuzumab had a better relapse-free survival than patients without trastuzumab treatment during the first 2–4 years of follow-up. Decrease in numbers or no change versus highly variable numbers or increase (fivefold or more) allowed to discriminate highly significantly and clearly (P < 0.0001, hazard ratio 5.5) between patients with a low or high risk of relapse. An increase in CETC was accompanied by an increasing portion of cells containing a very high number of HER2/neu gene amplificates.

Conclusions

Analysis of the behavior of CETC can, in the future, contribute to evaluate the efficacy of targeted therapy early during the course of the disease, sparing patients unnecessary treatment but also to reduce the costs for the health system and to downsize the extent and length of clinical studies.

[Intraductal application of Levovist® in salivary glands of animals]

BACKGROUND

Several methods are well established for the imaging of salivary glands. Excluding the invasive method sialendoscopy all other methods show the salivary duct system inadequately. The aim of this study is to demonstrate a method to visualize the salivary duct system by B-mode ultrasound.

MATERIAL AND METHODS

In 10 parotid glands of common pig cadavers the ultrasound contrast agent Levovist (®), which is galactose stabilized by palmitic acid was applied into the main salivary ducts while simultaneously performing a transcutaneous B-mode ultrasound.

RESULTS

In all cadavers a visualization of the salivary duct system could be achieved by the application of Levovist (®) because of contrast enhancement. This effect arises as a result of an increased reflection of ultrasound waves on the surface of the microbubbles contained in the contrast agent.

CONCLUSION

A reproducible visualization of the salivary duct system with B-mode ultrasound is possible by an intraductal application of an ultrasound contrast agent. In future this could be established as a reliable and fast method for imaging of the salivary ducts without ionizing radiation for the patient.

In vivo molecular imaging reveals distinct distributions of the serotonin transporter, the major inhibitory and excitatory serotonin receptors

Introduction

Based on evidences in molecular neuroimaging, postmortem and genetic studies, impaired serotonergic neurotransmission has been implicated with affective disorders. Moreover, a growing number of evidences showed strong interrelations within the serotonergic system suggesting a common mechanism in the modulation of receptor and transporter densities.

Objective

Here we directly investigated the regional expression of the 5-HT1A, 5-HT2A and 5-HTT using PET and the three highly selective and specific radioligands [carbonyl-11C]WAY-100635, [18F]Altanserin and [11C]DASB in healthy subjects.

Methods

A total of 55 healthy subjects (5-HT1A: 36 subjects, 18 males, age = 26.0 ± 4.9; 5-HT2A: 19 subjects, 11 males, age = 28.2 ± 5.9; 5-HTT: 8 males, age = 28.12 ± 3.6) were included in this study. Binding potential (BPND) values were quantified according to the AAL parcellation scheme.

Results

BPND values averaged over both hemispheres ranged from 0.40–6.35 for the 5-HT1A receptor; 0.01–2.01 for the 5-HT2A receptor and 0.09–2.05 for the 5-HTT, respectively. There was a specific topological pattern according to the ratio between the 5-HT1A, 5-HT2A receptors and 5-HTT (“fingerprints”).

Conclusions

Such information can be essential for detecting potential local alterations in the ratio between different binding proteins on a network level in pathological conditions.

Moreover, these data might provide further insight in area-specific effects of frequently prescribed selective serotonin re-uptake inhibitors (SSRI): 1)