No description available.

Background and aims: It is known that smooth muscle possesses substantial mechanical plasticity in that it is able to adapt to large changes in length without compromising its ability to generate force. It is believed that structural malleability of the contractile apparatus underlies this plasticity. There is strong evidence suggesting that myosin thick filaments of the muscle are relatively labile and their length in vivo is determined by the equilibrium between monomeric and filamentous myosin. The equilibrium in turn is governed by the state of phosphorylation of the 20-kD regulatory myosin light chain (MLC20, or RLC). It is known that phosphorylation of the myosin light chain favors formation of the filaments; it is not known how the light chain phosphorylation affects the lability of the filaments. The major aim of this thesis was to measure the mechanical integrity of the filaments formed from purified myosin molecules from bovine airway smooth muscle, and to determine whether the integrity was influenced by phosphorylation of the myosin light chain. Methods: Myosin was purified from bovine trachealis to form filaments, in ATP containing zero-calcium solution during a slow dialysis that gradually reduced the ionic strength. Sufficient myosin light chain kinase and phosphatase, as well as calmodulin, were retained after the myosin purification and this enabled phosphorylation of RLC within 20-40 s after addition of calcium to the filament suspension. The phosphorylated and non-phosphorylated filaments were then partially disassembled by ultrasonification. The extent of filament disintegration was visualized and quantified by atomic force microscopy. Results: RLC phosphorylation reduced the diameter of the filaments and rendered the filaments more resistant to ultrasonic agitation. Electron microscopy revealed a similar reduction in filament diameter in intact smooth muscle when the cells were activated. Conclusion: Our results suggest that RLC phosphorylation is a key regulatory step in modifying the structural properties of myosin filaments in smooth muscle, where formation and dissolution of the filaments are required in the cells’ adaptation to different cell length.

Bakgrund:Demens är en av de största folksjukdomarna i Sverige och är en obotbar sjukdom som är progredierande. Agitation är ett vanligt problem hos personer med en demenssjukdom och medför ofta stress både för den demensdrabbade, för anhöriga och vårdare. Farmakologiska behandlingar har en tveksam effekt och många biverkningar, vilket gör att omvårdnaden blir en viktig del i behandlingen. Syfte: Syftet var att beskriva betydelsen av olika former av icke-farmakologiska metoder för att minska agitation hos personer med en demenssjukdom. Metod:Vald metod var allmän litteraturstudie med beskrivande design. Elektronisk sökning gjordes i databaserna Cinahl, Medline, PsykINFO och Amed. Slutligen valdes nio artiklar att ingå i resultatet. Resultat: Resultatet visar att flertalet av de icke- farmakologiska metoderna som ingår i litteraturstudien ger en minskning av agiterande beteende. Dessa metoder är: favoritmusik, musikterapi i grupp, musik tillsammans med rörelser som gruppaktivitet, handmassage, akupressur, aromaterapi med lavendeldoft, Montessori- baserade aktiviteter i grupp, simulerade familjesamtal och olika individuella aktiviteter. Även ljusterapi ingår i litteraturstudien men resultatet har tveksamheter angående om effekten är gynnsam eller inte. Slutsats: Genom att använda sig av olika former av icke- farmakologiska metoder kan det agiterande beteendet minska hos personer med en demenssjukdom.

Thesis (M.A.) - Simon Fraser University, 2006. / Theses (Dept. of Gerontology) / Simon Fraser University. Also issued in digital format and available on the World Wide Web.

Background: Traumatic brain injury (TBI) patients are often sedated, yet sedation assessment scales have not been thoroughly studied in this population. This project inquiry describes the use of the Richmond Agitation Sedation Scale (RASS) in assessing sedation in TBI patients. Methods: A retrospective, descriptive analysis of 38 ventilated, sedated TBI patients was performed to describe 1) the characteristics of the study TBI population, 2) the use of the RASS to guide titration of sedation medication, and 3) the nursing perspective of a sedation titration protocol that includes the use of the RASS. Results: Prescribed RASS score for the study population was -2; the actual RASS score was -2.04 +/-1.05. The days spent on mechanical ventilation were 3.46 +/- 1.95. The Injury Severity Score (ISS) correlated with sedation titration (r = -0.373; p<.05). The ICD-9 code also correlated with the RASS (r = -0.400; p<0.05). There was no correlation between RASS and sedation titration (r = -0.061; p = 0.717). The majority of nurses perceived that when using the RASS, sedation level did not affect their feeling of accuracy of neurological assessment (56%), and the patient's agitation level did not affect their feeling of accurate neurological assessment (58%). Conclusion: While the degree of injury was associated with the ability of the TBI patient to maintain the prescribed RASS level, there was no association between the RASS score and sedation titration, indicating that in this small study, the RASS did not guide sedation titration in the TBI population. However, the time spent at the prescribed RASS level and days of mechanical ventilation, which was similar to reported norms, suggest that the RASS is an adequate tool for assessing sedation in the TBI population. From the nursing perspective, the use of the RASS was not a barrier in assessing sedation titration. To our knowledge, this is the first study to describe the use of RASS for assessment of sedation in TBI patients. Additional prospective studies are necessary to fully understand the ability of the RASS to guide sedation titration.

Background and aims: It is known that smooth muscle possesses substantial mechanical plasticity in that it is able to adapt to large changes in length without compromising its ability to generate force. It is believed that structural malleability of the contractile apparatus underlies this plasticity. There is strong evidence suggesting that myosin thick filaments of the muscle are relatively labile and their length in vivo is determined by the equilibrium between monomeric and filamentous myosin. The equilibrium in turn is governed by the state of phosphorylation of the 20-kD regulatory myosin light chain (MLC20, or RLC). It is known that phosphorylation of the myosin light chain favors formation of the filaments; it is not known how the light chain phosphorylation affects the lability of the filaments. The major aim of this thesis was to measure the mechanical integrity of the filaments formed from purified myosin molecules from bovine airway smooth muscle, and to determine whether the integrity was influenced by phosphorylation of the myosin light chain. Methods: Myosin was purified from bovine trachealis to form filaments, in ATP containing zero-calcium solution during a slow dialysis that gradually reduced the ionic strength. Sufficient myosin light chain kinase and phosphatase, as well as calmodulin, were retained after the myosin purification and this enabled phosphorylation of RLC within 20-40 s after addition of calcium to the filament suspension. The phosphorylated and non-phosphorylated filaments were then partially disassembled by ultrasonification. The extent of filament disintegration was visualized and quantified by atomic force microscopy. Results: RLC phosphorylation reduced the diameter of the filaments and rendered the filaments more resistant to ultrasonic agitation. Electron microscopy revealed a similar reduction in filament diameter in intact smooth muscle when the cells were activated. Conclusion: Our results suggest that RLC phosphorylation is a key regulatory step in modifying the structural properties of myosin filaments in smooth muscle, where formation and dissolution of the filaments are required in the cells’ adaptation to different cell length.

Doctor of Philosphy (PhD) / Agitation following traumatic brain injury (TBI) is characterised by a heightened state of activity with disorganised information processing that interferes with learning and achieving functional goals. This thesis outlines a series of studies across four research phases, investigating how occupational performance of adults with TBI is affected by agitated behaviour and information processing difficulties. Clinicians report the presence of agitation interferes with engagement in therapy and achievement of rehabilitation goals. Research Phase One used a retrospective chart review of 80 adults with severe TBI to identify a high incidence of agitated behaviour during inpatient TBI rehabilitation. Agitated behaviour was associated with lengthier rehabilitation admission, prolonged duration of post-traumatic amnesia (PTA), and poor cognitive functioning at discharge. The association between agitation and poor cognition persisted for at least two years after discharge, highlighting the significant impact of agitated behaviour on people’s ability to relearn cognitive skills for daily function. These initial research findings directed subsequent research phases, in which an information processing model was adopted to examine application of cognitive strategies during occupational performance. An emerging occupational therapy assessment, The Perceive, Recall, Plan and Perform (PRPP) System of Task Analysis, was selected as the primary method for evaluating how application of cognitive strategies during occupational performance is affected in agitated patients. Clinical utility of this measure was established in a case study of an adult demonstrating severely agitated behaviour during inpatient TBI rehabilitation, followed by examination of instrument reliability and validity with ten experienced occupational therapists and five adults with agitated behaviour following brain injury. The PRPP System of Task Analysis emerged as a valid and reliable method for determining strategy application deficits during occupational performance of adults with agitated behaviour, in acute stages of TBI rehabilitation. Consistent patterns of processing deficits were related to the Perceive and Recall Quadrants of the PRPP System. The assessment tool forms part of a dynamic, interactive assessment and intervention system. The PRPP System of Intervention was evaluated in the final research phase, using an experimental single case design with replication across eight adults. The effectiveness of PRPP Intervention was examined in comparison to conventional occupational therapy in an ABAB design. Efficacy of the PRPP Intervention was demonstrated, with patients applying significantly more information processing strategies to occupational performance tasks during PRPP Intervention than during conventional occupational therapy sessions. Agitated behaviour concurrently reduced over the period of the study. Relationships between information processing and agitated behaviour are hypothesised.

Doctor of Philosphy (PhD) / Agitation following traumatic brain injury (TBI) is characterised by a heightened state of activity with disorganised information processing that interferes with learning and achieving functional goals. This thesis outlines a series of studies across four research phases, investigating how occupational performance of adults with TBI is affected by agitated behaviour and information processing difficulties. Clinicians report the presence of agitation interferes with engagement in therapy and achievement of rehabilitation goals. Research Phase One used a retrospective chart review of 80 adults with severe TBI to identify a high incidence of agitated behaviour during inpatient TBI rehabilitation. Agitated behaviour was associated with lengthier rehabilitation admission, prolonged duration of post-traumatic amnesia (PTA), and poor cognitive functioning at discharge. The association between agitation and poor cognition persisted for at least two years after discharge, highlighting the significant impact of agitated behaviour on people’s ability to relearn cognitive skills for daily function. These initial research findings directed subsequent research phases, in which an information processing model was adopted to examine application of cognitive strategies during occupational performance. An emerging occupational therapy assessment, The Perceive, Recall, Plan and Perform (PRPP) System of Task Analysis, was selected as the primary method for evaluating how application of cognitive strategies during occupational performance is affected in agitated patients. Clinical utility of this measure was established in a case study of an adult demonstrating severely agitated behaviour during inpatient TBI rehabilitation, followed by examination of instrument reliability and validity with ten experienced occupational therapists and five adults with agitated behaviour following brain injury. The PRPP System of Task Analysis emerged as a valid and reliable method for determining strategy application deficits during occupational performance of adults with agitated behaviour, in acute stages of TBI rehabilitation. Consistent patterns of processing deficits were related to the Perceive and Recall Quadrants of the PRPP System. The assessment tool forms part of a dynamic, interactive assessment and intervention system. The PRPP System of Intervention was evaluated in the final research phase, using an experimental single case design with replication across eight adults. The effectiveness of PRPP Intervention was examined in comparison to conventional occupational therapy in an ABAB design. Efficacy of the PRPP Intervention was demonstrated, with patients applying significantly more information processing strategies to occupational performance tasks during PRPP Intervention than during conventional occupational therapy sessions. Agitated behaviour concurrently reduced over the period of the study. Relationships between information processing and agitated behaviour are hypothesised.

Thèse (M.Ps.)--Université Laval, 2002. / Bibliogr.: f. [68]-73. Publié aussi en version électronique.

Thèse (M.Ps.)--Université Laval, 2002. / Bibliogr. Publié aussi en version électronique.