University of Turku

About: University of Turku is a education organization based out in Turku, Finland. It is known for research contribution in the topics: Population & Galaxy. The organization has 16296 authors who have published 45124 publications receiving 1505428 citations. The organization is also known as: Turun yliopisto & Åbo universitet.

Diagnosing cognitive impairment and dementia in primary health care – a more active approach is needed

Abstract: Objective to determine the documentation rate of dementia in primary health care, the clinical characteristics of patients with documented and undocumented dementia, and the diagnostic evaluations made in cognitive impairment. Design cross-sectional population-based study with a retrospective review of medical history. Setting primary health care in the municipality of Lieto, Southwestern Finland. Subjects all the inhabitants aged 64 and over in Lieto. Participation rate 82%, numbers = 1260. Measurements assessment of dementia according to DSM-IV criteria, and severity according to Clinical Dementia Rating. Possible documentation of dementia and evaluations done were reviewed from primary health care medical records. Results 112 patients with dementia were found. The sensitivity of the general practitioners' judgment of dementia was 48.2% and the specificity 99.6%. The documentation rate of dementia was 73% in severe, 46% in moderate and 33% in mild dementia. A greater proportion of the patients with undocumented dementia were male (P = 0.003), lived at home (P = 0.003), coped better with the instrumental activities of daily living (P = 0.006), had more depression (P = 0.029) and milder dementia (P = 0.005) than patients with documented dementia. Thyroid stimulating hormone was measured in 51% of the patients with suspected memory impairment or dementia, B12 vitamin in 20%, and serum calcium in 18%. Twenty-eight per cent of the patients had been tested for cognitive function, 68% for depressive symptoms, and 88% for social abilities. Forty-two per cent of patients were referred to a specialist, 32% of patients who were over 75 years. Conclusions less than half of the patients with dementia had their diagnosis documented in primary care medical records. Documentation increased in more advanced dementia. The diagnostic evaluations for reversible causes of dementia were insufficient in primary care, and they were done at a late phase of cognitive impairment.

Cognitive reserve hypothesis: Pittsburgh Compound B and fluorodeoxyglucose positron emission tomography in relation to education in mild Alzheimer's disease

Abstract: Objective The reduced risk for Alzheimer's disease (AD) in high-educated individuals has been proposed to reflect brain cognitive reserve, which would provide more efficient compensatory mechanisms against the underlying pathology, and thus delayed clinical expression. Our aim was to find possible differences in brain amyloid ligand 11C-labeled Pittsburgh Compound B ([11C]PIB) uptake and glucose metabolism in high- and low-educated patients with mild AD. Methods Twelve high-educated and 13 low-educated patients with the same degree of cognitive deterioration were studied with PET using [11C]PIB and 18F-fluorodeoxyglucose as ligands. The between-group differences were analyzed with voxel-based statistical method, and quantitative data were obtained with automated region-of-interest analysis. Results High-educated patients showed increased [11C]PIB uptake in the lateral frontal cortex compared with low-educated patients. Moreover, high-educated patients had significantly lower glucose metabolic rate in the temporoparietal cortical regions compared with low-educated patients. Interpretation Our results suggesting more advanced pathological and functional brain changes in high-educated patients with mild AD are in accordance with the brain cognitive reserve hypothesis and point out the importance of development of reliable markers of underlying AD pathology for early AD diagnostics. Ann Neurol 2007

What causes latitudinal gradients in species diversity? Evolutionary processes and ecological constraints on swallowtail biodiversity

Abstract: The latitudinal diversity gradient (LDG) is one of the most striking ecological patterns on our planet. Determining the evolutionary causes of this pattern remains a challenging task. To address this issue, previous LDG studies have usually relied on correlations between environmental variables and species richness, only considering evolutionary processes indirectly. Instead, we use a phylogenetically integrated approach to investigate the ecological and evolutionary processes responsible for the global LDG observed in swallowtail butterflies (Papilionidae). We find evidence for the 'diversification rate hypothesis' with different diversification rates between two similarly aged tropical and temperate clades. We conclude that the LDG is caused by (1) climatically driven changes in both clades based on evidence of responses to cooling and warming events, and (2) distinct biogeographical histories constrained by tropical niche conservatism and niche evolution. This multidisciplinary approach provides new findings that allow better understanding of the factors that shape LDGs.

Leber's "plus": neurological abnormalities in patients with Leber's hereditary optic neuropathy.

Abstract: Previous studies suggest that Leber's hereditary optic neuropathy (LHON) may be a systemic disorder with manifestations in organs other than the optic nerves. To evaluate nervous system involvement 38 men and eight women with LHON were re-examined. The patients were divided into three groups according to mtDNA analysis--namely, patients with the 11778 or with the 3460 mutation and patients without these primary mutations. Fifty nine per cent of patients had neurological abnormalities but there was no significant difference between the three groups. Movement disorders were the most common finding; nine patients had constant postural tremor, one chronic motor tic disorder, and one parkinsonism with dystonia. Four patients had peripheral neuropathy with no other evident cause. Two patients had a multiple sclerosis-like syndrome; in both patients MRI showed changes in the periventricular white matter. Thoracic kyphosis occurred in seven patients, five of whom had the 3460 mutation. In one patient the 3460 mutation was associated with involvement of the brain stem. It is suggested that various movement disorders, multiple sclerosis-like illness, and deformities of the vertebral column may associate pathogenetically with LHON.

Individual tree biomass estimation using terrestrial laser scanning

Abstract: Determination of stem and crown biomass requires accurate measurements of individual tree stem, bark, branch and needles. These measurements are time-consuming especially for mature trees. Accurate field measurements can be done only in a destructive manner. Terrestrial laser scanning (TLS) measurements are a viable option for measuring the reference information needed. TLS measurements provide dense point clouds in which features describing biomass can be extracted for stem form and canopy dimensions. Existing biomass models do not utilise canopy size information and therefore TLS-based estimation methods should improve the accuracy of biomass estimation. The main objective of this study was to estimate single-tree-level aboveground biomass (AGB), based on models developed using TLS data. The modelling dataset included 64 laboratory-measured trees. Models were developed for total AGB, tree stem-, living branch- and dead branch biomass. Modelling results were also compared with existing individual tree-level biomass models and showed that AGB estimation accuracies were improved, compared with those of existing models. However, current biomass models based on diameter-at-breast height (DBH), tree height and species worked rather well for stem- and total biomass. TLS-based models improved estimation accuracies, especially estimation of branch biomass. We suggest the use of stem curve and crown size geometric measurements from TLS data as a basis for allometric biomass models rather than statistical three-dimensional point metrics, since TLS statistical metrics are dependent on various scanning parameters and tree neighbourhood characteristics.