Image Analysis of Neuronal and Glial Markers: Fluorescence Microscopical Applications

The usefulness of computer-assisted image analysis with particular emphasis on fluorescence microscopy was evaluated and exemplified. Problems associated with image pick-up and transfer between microscope and computer are discussed. The importance of fully supported software programs adjusted to the needs of histology are emphasized. One such system, the IBAS (Kontron/Zeiss, West Germany) has been found suitable for use also by people with little or no background computer knowledge. Three examples where image analysis clearly adds a unique quantitative dimension to the evaluation of the results have been presented. (1) Nerve density measurements: A semi-automatic interactive program was used to evaluate the potentially neurotoxic effects of hexachlorophene and chlorhexidine, two disinfectant agents, using an intraocular screening model in which the density of the sympathetic autonomic ground plexus of the iris is studied by Falck-Hillarp fluorescence histochemistry applied to iris whole mounts. Pronounced neurotoxic effects were described. Dopaminergic nerve density measurements in striatum following neurotoxic drug treatments correlate well with other measurements of degree of denervation. (2) Transmitter release and diffusion: Experimentally induced unilateral parkinsonism in rats can be counteracted by intrastriatal implants of chromaffine tissue. These grafts work by releasing large quantities of catecholamines which diffuse through host neuropil. Image analysis was used to characterize in detail the diffusion of catecholamines using Falck-Hillarp fluorescence histochemistry. Linear scans of fluorescence intensity and imaging fluorescence gradients using false color look-up tables enables fast visual quantitative interpretation of the results

Image Analysis of Neuronal and Glial Markers: Fluorescence Microscopical Applications

The usefulness of computer-assisted image analysis with particular emphasis on fluorescence microscopy was evaluated and exemplified. Problems associated with image pick-up and transfer between microscope and computer are discussed. The importance of fully supported software programs adjusted to the needs of histology are emphasized. One such system, the IBAS (Kontron/Zeiss, West Germany) has been found suitable for use also by people with little or no background computer knowledge. Three examples where image analysis clearly adds a unique quantitative dimension to the evaluation of the results have been presented. (1) Nerve density measurements: A semi-automatic interactive program was used to evaluate the potentially neurotoxic effects of hexachlorophene and chlorhexidine, two disinfectant agents, using an intraocular screening model in which the density of the sympathetic autonomic ground plexus of the iris is studied by Falck-Hillarp fluorescence histochemistry applied to iris whole mounts. Pronounced neurotoxic effects were described. Dopaminergic nerve density measurements in striatum following neurotoxic drug treatments correlate well with other measurements of degree of denervation. (2) Transmitter release and diffusion: Experimentally induced unilateral parkinsonism in rats can be counteracted by intrastriatal implants of chromaffine tissue. These grafts work by releasing large quantities of catecholamines which diffuse through host neuropil. Image analysis was used to characterize in detail the diffusion of catecholamines using Falck-Hillarp fluorescence histochemistry. Linear scans of fluorescence intensity and imaging fluorescence gradients using false color look-up tables enables fast visual quantitative interpretation of the results. (3) Morphometry of smeared and sectioned astrocytes: A program was used that calculated area and perimeter of smeared astrocytes stained with an antiserum against glial fibrillary acidic protein, GFA. A study of astrocyte growth from adolescence to senescence revealed continuous growth of astrocytes throughout life. In this case the extreme complexity of astrocyte morphology necessitated special interactive procedures to be used in which the experimenter can “retouch” the digitized image prior to binary transformation. Area and perimeter data of this kind could not have been obtained without an image processing system. Astrocyte overgrowth in brain tissue grafts to the anterior chamber of the eye and to the brain were also described. It is concluded that image analysis is a powerful tool for the quantitative evaluation of microscopical images with general usefulness in flourescene histochemistry

Differences in diagnostic process, treatment and social support for Alzheimer's dementia between primary and specialist care : results from the Swedish Dementia Registry

BACKGROUND: the increasing prevalence of Alzheimer's dementia (AD) has shifted the burden of management towards primary care (PC). Our aim is to compare diagnostic process and management of AD in PC and specialist care (SC). DESIGN: cross-sectional study. SUBJECTS: a total of, 9,625 patients diagnosed with AD registered 2011-14 in SveDem, the Swedish Dementia Registry. METHODS: descriptive statistics are shown. Odds ratios are presented for test performance and treatment in PC compared to SC, adjusted for age, sex, Mini-Mental State Examination (MMSE) and number of medication. RESULTS: a total of, 5,734 (60%) AD patients from SC and 3,891 (40%) from PC. In both, 64% of patients were women. PC patients were older (mean age 81 vs. 76; P < 0.001), had lower MMSE (median 21 vs. 22; P < 0.001) and more likely to receive home care (31% vs. 20%; P < 0.001) or day care (5% vs. 3%; P < 0.001). Fewer diagnostic tests were performed in PC and diagnostic time was shorter. Basic testing was less likely to be complete in PC. The greatest differences were found for neuroimaging (82% in PC vs. 98% in SC) and clock tests (84% vs. 93%). These differences remained statistically significant after adjusting for MMSE and demographic characteristics. PC patients received less antipsychotic medication and more anxiolytics and hypnotics, but there were no significant differences in use of cholinesterase inhibitors between PC and SC. CONCLUSION: primary and specialist AD patients differ in background characteristics, and this can influence diagnostic work-up and treatment. PC excels in restriction of antipsychotic use. Use of head CT and clock test in PC are areas for improvement in Sweden

Feasibility and therapeutical potential of local intracerebral encapsulated cell biodelivery of BDNF to App NL−G−F knock-in Alzheimer mice

Abstract Background Alzheimer’s disease (AD) is an age-related disease characterized by altered cognition, neuroinflammation, and neurodegeneration against which there is presently no effective cure. Brain-derived neurotrophic factor (BDNF) is a key neurotrophin involved in the learning and memory process, with a crucial role in synaptic plasticity and neuronal survival. Several findings support that a reduced BDNF expression in the human brain is associated with AD pathogenesis. BDNF has been proposed as a potential therapy for AD, but BDNF has low brain penetration. In this study, we used an innovative encapsulated cell biodelivery (ECB) device, containing genetically modified cells capable of releasing BDNF and characterized its feasibility and therapeutic effects in the novel App knock-in AD mouse model (App NL−G−F ). Methods ECB’s containing human ARPE-19 cells genetically modified to release BDNF (ECB-BDNF devices) were stereotactically implanted bilaterally into hippocampus of 3-month-old App NL−G−F mice. The stability of BDNF release and its effect on AD pathology were evaluated after 1, 2-, and 4-months post-implantation by immunohistochemical and biochemical analyses. Exploratory and memory performance using elevated plus maze (EPM) and Y-maze test were performed in the 4-months treatment group. Immunological reaction towards ECB-BDNF devices were studied under ex vivo and in vivo settings. Results The surgery and the ECB-BDNF implants were well tolerated without any signs of unwanted side effects or weight loss. ECB-BDNF devices did not induce host-mediated immune response under ex vivo set-up but showed reduced immune cell attachment when explanted 4-months post-implantation. Elevated BDNF staining around ECB-BDNF device proximity was detected after 1, 2, and 4 months treatment, but the retrieved devices showed variable BDNF release. A reduction of amyloid-β (Aβ) plaque deposition was observed around ECB-BDNF device proximity after 2-months of BDNF delivery. Conclusions The result of this study supports the use of ECB device as a promising drug-delivery approach to locally administer BBB-impermeable factors for treating neurodegenerative conditions like AD. Optimization of the mouse-sized devices to reduce variability of BDNF release is needed to employ the ECB platform in future pre-clinical research and therapy development studies