Dietary Tyrosine Intake (FFQ) Is Associated with Locus Coeruleus, Attention and Grey Matter Maintenance: An MRI Structural Study on 398 Healthy Individuals of the Berlin Aging Study-II.

BACKGROUND AND OBJECTIVE: It is documented that low protein and amino-acid dietary intake is related to poorer cognitive health and increased risk of dementia. Degradation of the neuromodulatory pathways, (comprising the cholinergic, dopaminergic, serotoninergic and noradrenergic systems) is observed in neurodegenerative diseases and impairs the proper biosynthesis of key neuromodulators from micro-nutrients and amino acids. How these micro-nutrients are linked to neuromodulatory pathways in healthy adults is less studied. The Locus Coeruleus-Noradrenergic System (LC-NA) is the earliest subcortical structure affected in Alzheimer's disease, showing marked neurodegeneration, but is also sensitive for age-related changes. The LC-NA system is critical for supporting attention and cognitive control, functions that are enhanced both by tyrosine administration and chronic tyrosine intake. The purpose of this study was to 1) investigate whether the dietary intake of tyrosine, the key precursor for noradrenaline (NA), is related to LC signal intensity 2) whether LC mediates the reported association between tyrosine intake and higher cognitive performance (measured with Trail Making Test - TMT), and 3) whether LC signal intensity relates to an objective measure of brain maintenance (BrainPAD). METHODS: The analyses included 398 3T MRIs of healthy participants from the Berlin Aging Study II to investigate the relationship between LC signal intensity and habitual dietary tyrosine intake-daily average (HD-Tyr-IDA - measured with Food Frequency Questionnaire - FFQ). As a control procedure, the same analyses were repeated on other main seeds of the neuromodulators' subcortical system (Dorsal and Medial Raphe, Ventral Tegmental Area and Nucleus Basalis of Meynert). In the same way, the relationships between the five nuclei and BrainPAD were tested. RESULTS: Results show that HD-Tyr-IDA is positively associated with LC signal intensity. Similarly, LC disproportionally relates to better brain maintenance (BrainPAD). Mediation analyses reveal that only LC, relative to the other nuclei tested, mediates the relationship between HD-Tyr-IDA I and performance in the TMT and between HD-Tyr-IDA and BrainPAD. CONCLUSIONS: These findings provide the first evidence linking tyrosine intake with LC-NA system signal intensity and its correlation with neuropsychological performance. This study strengthens the role of diet for maintaining brain and cognitive health and supports the noradrenergic theory of cognitive reserve. Within this framework, adequate tyrosine intake might increase the resilience of LC-NA system functioning, by preventing degeneration and supporting noradrenergic metabolism required for LC function and neuropsychological performance.

Discrete-choice experiment to analyse preferences for centralizing specialist cancer surgery services.

BACKGROUND: Centralizing specialist cancer surgery services aims to reduce variations in quality of care and improve patient outcomes, but increases travel demands on patients and families. This study aimed to evaluate preferences of patients, health professionals and members of the public for the characteristics associated with centralization. METHODS: A discrete-choice experiment was conducted, using paper and electronic surveys. Participants comprised: former and current patients (at any stage of treatment) with prostate, bladder, kidney or oesophagogastric cancer who previously participated in the National Cancer Patient Experience Survey; health professionals with experience of cancer care (11 types including surgeons, nurses and oncologists); and members of the public. Choice scenarios were based on the following attributes: travel time to hospital, risk of serious complications, risk of death, annual number of operations at the centre, access to a specialist multidisciplinary team (MDT) and specialist surgeon cover after surgery. RESULTS: Responses were obtained from 444 individuals (206 patients, 111 health professionals and 127 members of the public). The response rate was 52·8 per cent for the patient sample; it was unknown for the other groups as the survey was distributed via multiple overlapping methods. Preferences were particularly influenced by risk of complications, risk of death and access to a specialist MDT. Participants were willing to travel, on average, 75 min longer in order to reduce their risk of complications by 1 per cent, and over 5 h longer to reduce risk of death by 1 per cent. Findings were similar across groups. CONCLUSION: Respondents' preferences in this selected sample were consistent with centralization.

Methods for estimating detection efficiency and tracking acoustic tags with mobile transect surveys.

Mobile transect surveys were conducted for 5 years in a deep fjord looking for weak acoustic tags, most of which were in dead fishes lying on the seabed. Detection efficiencies were quantified because inferences about fish presence were made from tag detection data but a considerable proportion of tags were not detected. Methods for assessing transect widths using cumulative probabilities of measured perpendicular distances from blind transect lines to triangulated tag locations are described. Three methods for estimating detection efficiencies are presented: fitting attenuation functions to perpendicular distance data, simultaneous use of two receiver systems and test tag surveys. Several factors that influenced these detection efficiencies and ranges are shown, including boat speed, depth of tag, tag type, different hydrophone-receiver systems and variation among individual hydrophones and receivers of the same model. The trade-off between detection efficiency per unit area and area swept is discussed, which is largely based on boat speed during transects. Finally, several methods are suggested for increasing decoding efficiencies in mobile tracking studies when tags are heard but are difficult to decode.

[Identification of the hop latent virus on the varieties of Ukrainian selection]. / Diahnostyka latentnoho virusu khmeliu na sortakh ukraïns'koï selektsiï.

Hop latent virus diagnostic of the hop gardens of the modern varieties in Ukraine has been made. Biomolecular diagnosticum has been developed using own primers and conditions for PCR method in combination with classical techniques of biological testing, electron microscopy and double strain RNA extraction from the infected plants.

Automated enzymatic assay for plasma ammonia.

An enzymatic method for determining plasma ammonia with the Du Pont Automatic Clinical Analyzer (aca) is described. The assay requires a sample volume of 500 muL for a kinetic ammonia measurement. The reaction is initiated with glutamate dehydrogenase and the rate of depletion of NADPH is monitored with two measurements, 17 s apart, at 340 nm. Reaction conditions have been optimized for maximum sensitivity through both one-factor-at-a-time and multiple variable response surface optimization techniques. Linearity to 1000 mumol of ammonia per liter of plasma has been achieved. No significant interferences were observed from anticoagulants or endogenous blood components, including pyruvate and oxalacetate. Use of the coenzyme NADPH (instead of NADH) in this aca procedure eliminates the lengthy pre-incubation otherwise required for endogenous dehydrogenase reactions.