19 resultados para fall prediction model of elderly

em Helda - Digital Repository of University of Helsinki


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Research on unit cohesion has shown positive correlations between cohesion and valued outcomes such as strong performance, reduced stress, less indiscipline, and high re-enlistment intentions. However, the correlations have varied in strength and significance. The purpose of this study is to show that taking into consideration the multi-component nature of cohesion and relating the most applicable components to specific outcomes could resolve much of the inconsistency. Unit cohesion is understood as a process of social integration among members of a primary group with its leaders, and with the larger secondary groups of which they are a part. Correspondingly, included in the framework are four bonding components: horizontal (peer) and vertical (subordinate and leader) and organizational and institutional, respectively. The data were collected as part of a larger research project on cohesion, leadership, and personal adjustment to the military. In all, 1,534 conscripts responded to four questionnaires during their service in 2001-2002. In addition, sociometric questionnaires were given to 537 group members in 47 squads toward the end of their service. The results showed that platoons with strong primary-group cohesion differed from other platoons in terms of performance, training quality, secondary-group experiences, and attitudes toward refresher training. On the sociometric level it was found that soldiers who were chosen as friends by others were more likely to have higher expected performance, better performance ratings, more positive attitudes toward military service, higher levels of well-being during conscript service, and fewer exemptions from duty during it. On the group level, the selection of the respondents own group leader rather than naming a leader from outside (i.e., leader bonding) had a bearing not only on cohesion and performance, but also on the social, attitudinal, and behavioral criteria. Overall, the aim of the study was to contribute to the research on cohesion by introducing a model that takes into account the primary foci of bonding and their impact. The results imply that primary-group and secondary-group bonding processes are equally influential in explaining individual and group performance, whereas the secondary-group bonding components are far superior in explaining career intentions, personal growth, avoidance of duty, and attitudes toward refresher training and national defense. This should be considered in the planning and conducting of training. The main conclusion is that the different types of cohesion components have a unique, positive, significant, but varying impact on a wide range of criteria, confirming the need to match the components with the specific criteria.

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Parkinson’s disease (PD) is the second most common neurodegenerative disease among the elderly. Its etiology is unknown and no disease-modifying drugs are available. Thus, more information concerning its pathogenesis is needed. Among other genes, mutated PTEN-induced kinase 1 (PINK1) has been linked to early-onset and sporadic PD, but its mode of action is poorly understood. Most animal models of PD are based on the use of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MPTP is metabolized to MPP+ by monoamine oxidase B (MAO B) and causes cell death of dopaminergic neurons in the substantia nigra in mammals. Zebrafish has been a widely used model organism in developmental biology, but is now emerging as a model for human diseases due to its ideal combination of properties. Zebrafish are inexpensive and easy to maintain, develop rapidly, breed in large quantities producing transparent embryos, and are readily manipulated by various methods, particularly genetic ones. In addition, zebrafish are vertebrate animals and results derived from zebrafish may be more applicable to mammals than results from invertebrate genetic models such as Drosophila melanogaster and Caenorhabditis elegans. However, the similarity cannot be taken for granted. The aim of this study was to establish and test a PD model using larval zebrafish. The developing monoaminergic neuronal systems of larval zebrafish were investigated. We identified and classified 17 catecholaminergic and 9 serotonergic neuron populations in the zebrafish brain. A 3-dimensional atlas was created to facilitate future research. Only one gene encoding MAO was found in the zebrafish genome. Zebrafish MAO showed MAO A-type substrate specificity, but non-A-non-B inhibitor specificity. Distribution of MAO in larval and adult zebrafish brains was both diffuse and distinctly cellular. Inhibition of MAO during larval development led to markedly elevated 5-hydroxytryptamine (serotonin, 5-HT) levels, which decreased the locomotion of the fish. MPTP exposure caused a transient loss of cells in specific aminergic cell populations and decreased locomotion. MPTP-induced changes could be rescued by the MAO B inhibitor deprenyl, suggesting a role for MAO in MPTP toxicity. MPP+ affected only one catecholaminergic cell population; thus, the action of MPP+ was more selective than that of MPTP. The zebrafish PINK1 gene was cloned in zebrafish, and morpholino oligonucleotides were used to suppress its expression in larval zebrafish. The functional domains and expression pattern of zebrafish PINK1 resembled those of other vertebrates, suggesting that zebrafish is a feasible model for studying PINK1. Translation inhibition resulted in cell loss of the same catecholaminergic cell populations as MPTP and MPP+. Inactivation of PINK1 sensitized larval zebrafish to subefficacious doses of MPTP, causing a decrease in locomotion and cell loss in one dopaminergic cell population. Zebrafish appears to be a feasible model for studying PD, since its aminergic systems, mode of action of MPTP, and functions of PINK1 resemble those of mammalians. However, the functions of zebrafish MAO differ from the two forms of MAO found in mammals. Future studies using zebrafish PD models should utilize the advantages specific to zebrafish, such as the ability to execute large-scale genetic or drug screens.

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Heart failure is a common and highly challenging medical disorder. The progressive increase of elderly population is expected to further reflect in heart failure incidence. Recent progress in cell transplantation therapy has provided a conceptual alternative for treatment of heart failure. Despite improved medical treatment and operative possibilities, end-stage coronary artery disease present a great medical challenge. It has been estimated that therapeutic angiogenesis would be the next major advance in the treatment of ischaemic heart disease. Gene transfer to augment neovascularization could be beneficial for such patients. We employed a porcine model to evaluate the angiogenic effect of vascular endothelial growth factor (VEGF)-C gene transfer. Ameroid-generated myocardial ischemia was produced and adenovirus encoding (ad)VEGF-C or β-galactosidase (LacZ) gene therapy was given intramyocardially during progressive coronary stenosis. Angiography, positron emission tomography (PET), single photon emission computed tomography (SPECT) and histology evidenced beneficial affects of the adVEGF-C gene transfer compared to adLacZ. The myocardial deterioration during progressive coronary stenosis seen in the control group was restrained in the treatment group. We observed an uneven occlusion rate of the coronary vessels with Ameroid constrictor. We developed a simple methodological improvement of Ameroid model by ligating of the Ameroid–stenosed coronary vessel. Improvement of the model was seen by a more reliable occlusion rate of the vessel concerned and a formation of a rather constant myocardial infarction. We assessed the spontaneous healing of the left ventricle (LV) in this new model by SPECT, PET, MRI, and angiography. Significant spontaneous improvement of myocardial perfusion and function was seen as well as diminishment of scar volume. Histologically more microvessels were seen in the border area of the lesion. Double staining of the myocytes in mitosis indicated more cardiomyocyte regeneration at the remote area of the lesion. The potential of autologous myoblast transplantation after ischaemia and infarction of porcine heart was evaluated. After ligation of stenosed coronary artery, autologous myoblast transplantation or control medium was directly injected into the myocardium at the lesion area. Assessed by MRI, improvement of diastolic function was seen in the myoblast-transplanted animals, but not in the control animals. Systolic function remained unchanged in both groups.

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Numerical models, used for atmospheric research, weather prediction and climate simulation, describe the state of the atmosphere over the heterogeneous surface of the Earth. Several fundamental properties of atmospheric models depend on orography, i.e. on the average elevation of land over a model area. The higher is the models' resolution, the more the details of orography directly influence the simulated atmospheric processes. This sets new requirements for the accuracy of the model formulations with respect to the spatially varying orography. Orography is always averaged, representing the surface elevation within the horizontal resolution of the model. In order to remove the smallest scales and steepest slopes, the continuous spectrum of orography is normally filtered (truncated) even more, typically beyond a few gridlengths of the model. This means, that in the numerical weather prediction (NWP) models, there will always be subgridscale orography effects, which cannot be explicitly resolved by numerical integration of the basic equations, but require parametrization. In the subgrid-scale, different physical processes contribute in different scales. The parametrized processes interact with the resolved-scale processes and with each other. This study contributes to building of a consistent, scale-dependent system of orography-related parametrizations for the High Resolution Limited Area Model (HIRLAM). The system comprises schemes for handling the effects of mesoscale (MSO) and small-scale (SSO) orographic effects on the simulated flow and a scheme of orographic effects on the surface-level radiation fluxes. Representation of orography, scale-dependencies of the simulated processes and interactions between the parametrized and resolved processes are discussed. From the high-resolution digital elevation data, orographic parameters are derived for both momentum and radiation flux parametrizations. Tools for diagnostics and validation are developed and presented. The parametrization schemes applied, developed and validated in this study, are currently being implemented into the reference version of HIRLAM.

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Background: Malnutrition is a common problem for residents of nursing homes and long-term care hospitals. It has a negative influence on elderly residents and patients health and quality of life. Nutritional care seems to have a positive effect on elderly individuals nutritional status and well-being. Studies of Finnish elderly people s nutrition and nutritional care in institutions are scarce. Objectives: The primary aim was to investigate the nutritional status and its associated factors of elderly nursing home residents and long-term care patients in Finland. In particular, to find out, if the nursing or nutritional care factors are associated with the nutritional status, and how do carers and nurses recognize malnutrition. A further aim was to assess the energy and nutrient intake of the residents of dementia wards. A final objective was to find out, if the nutrition training of professionals leads to changes in their knowledge and further translate into better nutrition for the aged residents of dementia wards. Subjects and methods: The residents (n=2114) and patients (n=1043) nutritional status was assessed in all studies using the Mini Nutritional Assessment test (MNA). Information was gathered in a questionnaire on residents and patients daily routines providing nutritional care. Residents energy and nutrient intake (n=23; n=21) in dementia wards were determined over three days by the precise weighing method. Constructive learning theory was the basis for educating the professionals (n=28). A half-structured questionnaire was used to assess professionals learning. Studies I-IV were cross-sectional studies whereas study V was an intervention study. Results: Malnutrition was common among elderly residents and patients living in nursing homes and hospitals in Finland. According to the MNA, 11% to 57% of the studied elderly people suffered from malnutrition, and 40-89% were at risk of malnutrition, whereas only 0-16% had a good nutritional status. Resident- and patient-related factors such as dementia, impaired ADL (Activities of Daily Living), swallowing difficulties and constipation mainly explained the malnutrition, but also some nutritional care related factors, such as eating less than half of the offered food portion and not receiving snacks were also related to malnutrition. The intake of energy and some nutrients by the residents of dementia wards were lower than those recommended, although the offered food contained enough energy and nutrients. The proportion of residents receiving vitamin D supplementation was low, although there is a recommendation and known benefits for the adequate intake of vitamin D. Nurses recognized malnutrition poorly, only one in four (26.7%) of the actual cases. Keeping and analysing food diaries and reflecting on nutritional issues in small group discussions were effective training methods for professionals. The nutrition education of professionals had a positive impact on the energy and protein intake, BMIs, and the MNA scores of some residents in dementia wards. Conclusions: Malnutrition was common among elderly residents and patients living in nursing homes and hospitals in Finland. Although residents- and patient related factors mainly explained malnutrition, nurses recognized malnutrition poorly and nutritional care possibilities were in minor use. Professionals nutrition education had a positive impact on the nutrition of elderly residents. Further studies describing successful nutritional care and nutrition education of professionals are needed.

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Colorectal cancer is among the major cancers and one of the leading causes of cancer-related deaths in Western societies. Its occurrence is strongly affected by environmental factors such as diet. Thus, for preventative strategies it is vitally important to understand the mechanisms that stimulate adenoma growth and development towards accelerated malignancy or, in contrast, attenuate them to remain in quiescence for periods as long as decades. The main objective of this study was to investigate whether diet is able to modulate β-catenin signalling related to the promotion or prevention of intestinal tumourigenesis in an animal model of colon cancer, the Min/+ mouse. A series of dietary experiments with Min/+ mice were performed where fructo-oligosaccharide inulin was used for tumour promotion and four berries, bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), cloudberry (Rubus chamaemorus) and white currant (Ribes x pallidum), were used for tumour prevention. The adenomas (Apc-/-) and surrounding normal-appearing mucosa (Apc+/-) were investigated separately due to their mutational and functional differences. Tumour promotive and preventive diets had opposite effects on β-catenin signalling in the adenomas that was related to the different adenoma growth effects of dietary inulin and berries. The levels of nuclear β-catenin and cyclin D1 combined with size of the adenomas in the treatment groups suggests that diets induced differences in the cancerous process. Adenomas progressing to malignant carcinomas are most likely found in the sub-groups having the highest levels of β-catenin. On the other hand, adenomas staying quiescent for a long period of time are most probably found in the cloudberry or white currant diet groups. The levels of membranous E-cadherin and β-catenin increased as the adenomas in the inulin diet group grew, which could be a result of the overall increase in the protein levels of the cell. Therefore, the increasing levels of membranous β-catenin in Min/+ mice adenomas would be undesirable, due to the simultaneous increase in oncogenic nuclear β-catenin. We propose that the decreased amount of membranous β-catenin in benign adenomas of berry groups also means a decrease in the nuclear pool of β-catenin. Tumour promotion, but not the tumour prevention, influenced β-catenin signalling already in the normal appearing mucosa. Inulin-induced tumour promotion was related to β-catenin signalling in Min/+ mice, and in WT mice changes were also visible. The preventative effects of berries in the initiation phase were not mediated by β-catenin signalling. Our results suggest that, in addition to the number, size, and growth rate of adenomatous polyps, the signalling pattern of the adenomas should be considered when evaluating preventative dietary strategies.

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This thesis clarifies important molecular pathways that are activated during the cell death observed in Huntington’s disease. Huntington’s disease is one of the most common inherited neurodegenerative diseases, which is primarily inherited in an autosomal dominant manner. HD is caused by an expansion of CAG repeats in the first exon of the IT15 gene. IT15 encodes the production of a Huntington’s disease protein huntingtin. Mutation of the IT15 gene results in a long stretch of polyQ residues close to the amino-terminal region of huntingtin. Huntington’s disease is a fatal autosomal neurodegenerative disorder. Despite the current knowledge of HD, the precise mechanism behind the selective neuronal death, and how the disease propagates, still remains an enigma. The studies mainly focused on the control of endoplasmic reticulum (ER) stress triggered by the mutant huntingtin proteins. The ER is a delicate organelle having essential roles in protein folding and calcium regulation. Even the slightest perturbations on ER homeostasis are effective enough to trigger ER stress and its adaptation pathways, called unfolded protein response (UPR). UPR is essential for cellular homeostasis and it adapts ER to the changing environment and decreases ER stress. If adaptation processes fail and stress is excessive and prolonged; irreversible cell death pathways are engaged. The results showed that inhibition of ER stress with chemical agents are able to decrease cell death and formation of toxic cell aggregates caused by mutant huntingtin proteins. The study concentrated also to the NF-κB (nuclear factor-kappaB) pathway, which is activated during ER stress. NF-κB pathway is capable to regulate the levels of important cellular antioxidants. Cellular antioxidants provide a first line of defence against excess reactive oxygen species. Excess accumulation of reactive oxygen species and subsequent activation of oxidative stress damages motley of vital cellular processes and induce cell degeneration. Data showed that mutant huntingtin proteins downregulate the expression levels of NF-κB and vital antioxidants, which was followed by increased oxidative stress and cell death. Treatment with antioxidants and inhibition of oxidative stress were able to counteract these adverse effects. In addition, thesis connects ER stress caused by mutant huntingtin to the cytoprotective autophagy. Autophagy sustains cellular balance by degrading potentially toxic cell proteins and components observed in Huntington’s disease. The results revealed that cytoprotective autophagy is active at the early points (24h) of ER stress after expression of mutant huntingtin proteins. GADD34 (growth arrest and DNA damage-inducible gene 34), which is previously connected to the regulation of translation during cell stress, was shown to control the stimulation of autophagy. However, GADD34 and autophagy were downregulated at later time points (48h) during mutant huntingtin proteins induced ER stress, and subsequently cell survival decreased. Overexpression GADD34 enhanced autophagy and decreased cell death, indicating that GADD34 plays a critical role in cell protection. The thesis reveales new interesting data about the neuronal cell death pathways seen in Huntington’s disease, and how cell degeneration is partly counteracted by various therapeutic agents. Expression of mutant huntingtin proteins is shown to alter signaling events that control ER stress, oxidative stress and autophagy. Despite that Huntington’s disease is mainly an untreatable disorder; these findings offer potential targets and neuroprotective strategies in designing novel therapies for Huntington’s disease.

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Parkinson s disease (PD) is a neurodegenerative disorder associated with a progressive loss of dopaminergic neurons of the substantia nigra (SN). Current therapies of PD do not stop the progression of the disease and the efficacy of these treatments wanes over time. Neurotrophic factors are naturally occurring proteins promoting the survival and differentiation of neurons and the maintenance of neuronal contacts. Neurotrophic factors are attractive candidates for neuroprotective or even neurorestorative treatment of PD. Thus, searching for and characterizing trophic factors are highly important approaches to degenerative diseases. CDNF (cerebral dopamine neurotrophic factor) and MANF (mesencephalic astrocyte-derived neurotrophic factor) are secreted proteins that constitute a novel, evolutionarily conserved neurotrophic factor family expressed in vertebrates and invertebrates. The present study investigated the neuroprotective and restorative effects of human CDNF and MANF in rats with unilateral partial lesion of dopamine neurons by 6-hydroxydopamine (6-OHDA) using both behavioral (amphetamine-induced rotation) and immunohistochemical analyses. We also investigated the distribution and transportation profiles of intrastriatally injected CDNF and MANF in rats. Intrastriatal CDNF and MANF protected nigrostriatal dopaminergic neurons when administered six hours before or four weeks after the neurotoxin 6-OHDA. More importantly, the function of the lesioned nigrostriatal dopaminergic system was partially restored even when the neurotrophic factors were administered four weeks after 6-OHDA. A 14-day continuous infusion of CDNF but not of MANF restored the function of the midbrain neural circuits controlling movement when initiated two weeks after unilateral injection of 6-OHDA. Continuous infusion of CDNF also protected dopaminergic TH-positive cell bodies from toxin-induced degeneration in the substantia nigra pars compacta (SNpc) and fibers in the striatum. When injected into the striatum, CDNF and GDNF had similar transportation profiles from the striatum to the SNpc; thus CDNF may act via the same nerve tracts as GDNF. Intrastriatal MANF was transported to cortical areas which may reflect a mechanism of neurorestorative action that is different from that of CDNF and GDNF. CDNF and MANF were also shown to distribute more readily than GDNF. In conclusion, CDNF and MANF are potential therapeutic proteins for the treatment of PD.

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A model of the information and material activities that comprise the overall construction process is presented, using the SADT activity modelling methodology. The basic model is further refined into a number of generic information handling activities such as creation of new information, information search and retrieval, information distribution and person-to-person communication. The viewpoint could be described as information logistics. This model is then combined with a more traditional building process model, consisting of phases such as design and construction. The resulting two-dimensional matrix can be used for positioning different types of generic IT-tools or construction specific applications. The model can thus provide a starting point for a discussion of the application of information and communication technology in construction and for measurements of the impacts of IT on the overall process and its related costs.