Search

Bakgrunn: Kroniske søvnvansker har blitt vanligere de siste årene. Omtrent halvparten av alle eldre opplever søvnproblemer. På sykehjem bruker hver fjerde pasient sovemedisin, og til tross for anbefalinger om kortvarig bruk, står mange på medisinene i år etter år. Dette kan ha alvorlige bivirkninger. Hensikten med oppgaven er å få kunnskap om ikke-medikamentelle sykepleietiltak rettet mot søvnvansker hos eldre sykehjemsbeboere, som dermed kan bli brukt alternativt til administrering av sovemedisiner. Metode: Litteraturstudien er basert på 9 kvantitative forskningsstudier. Søkene ble gjort i Medline og Cinahl. Resultat: Søvnproblemer hos eldre sykehjemsbeboere forekommer hyppig, og påvirkes av både fysiske, psykososiale og miljømessige faktorer. Fysisk og sosial aktivitet kan ha en positiv effekt, samt implementering av metoder fra kognitiv adferdsterapi for insomni. Konklusjon: Det er flere ikke-medikamentelle tiltak som viser å ha god effekt på søvnen til eldre sykehjemsbeboere, og som kan gjennomføres av en sykepleier. Likevel kan gjennomføring være utfordrende som følge av underbemanning.

Changes in mitochondrial amount and shape are intimately linked to maintenance of cell homeostasis via adaptation of vital functions. Here, we developed a new live-cell reporter strategy to simultaneously monitor mitochondrial biogenesis and morphology. This was achieved by making a genetic reporter construct where a master regulator of mitochondrial biogenesis, nuclear respiratory factor 1 (NRF-1), controls expression of mitochondria targeted green fluorescent protein (mitoGFP). HeLa cells with the reporter construct demonstrated inducible expression of mitoGFP upon activation of AMP-dependent protein kinase (AMPK) with AICAR. We established stable reporter cells where the mitoGFP reporter activity corresponded with mitochondrial biogenesis both in magnitude and kinetics, as confirmed by biochemical markers and confocal microscopy. Quantitative 3D image analysis confirmed accordant increase in mitochondrial biomass, in addition to filament/network promoting and protecting effects on mitochondrial morphology, after treatment with AICAR. The level of mitoGFP reversed upon removal of AICAR, in parallel with decrease in mtDNA. In summary, we here present a new GFP-based genetic reporter strategy to study mitochondrial regulation and dynamics in living cells. This combinatorial reporter concept can readily be transferred to other cell models and contexts to address specific physiological mechanisms. publishedVersion

Mitochondrial morphology and function are coupled in healthy cells, during pathological conditions and (adaptation to) endogenous and exogenous stress. In this sense mitochondrial shape can range from small globular compartments to complex filamentous networks, even within the same cell. Understanding how mitochondrial morphological changes (i.e. “mitochondrial dynamics”) are linked to cellular (patho) physiology is currently the subject of intense study and requires detailed quantitative information. During the last decade, various computational approaches have been developed for automated 2-dimensional (2D) analysis of mitochondrial morphology and number in microscopy images. Although these strategies are well suited for analysis of adhering cells with a flat morphology they are not applicable for thicker cells, which require a three-dimensional (3D) image acquisition and analysis procedure. Here we developed and validated an automated image analysis algorithm allowing simultaneous 3D quantification of mitochondrial morphology and network properties in human endothelial cells (HUVECs). Cells expressing a mitochondria-targeted green fluorescence protein (mitoGFP) were visualized by 3D confocal microscopy and mitochondrial morphology was quantified using both the established 2D method and the new 3D strategy. We demonstrate that both analyses can be used to characterize and discriminate between various mitochondrial morphologies and network properties. However, the results from 2D and 3D analysis were not equivalent when filamentous mitochondria in normal HUVECs were compared with circular/spherical mitochondria in metabolically stressed HUVECs treated with rotenone (ROT). 2D quantification suggested that metabolic stress induced mitochondrial fragmentation and loss of biomass. In contrast, 3D analysis revealed that the mitochondrial network structure was dissolved without affecting the amount and size of the organelles. Thus, our results demonstrate that 3D imaging and quantification are crucial for proper understanding of mitochondrial shape and topology in non-flat cells. In summary, we here present an integrative method for unbiased 3D quantification of mitochondrial shape and network properties in mammalian cells. publishedVersion