| 1. |
- Lee, Hyun Ju, et al.
(författare)
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Intricate role of water in proton transport through cytochrome c oxidase
- 2010
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 132:45, s. 16225-16239
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Tidskriftsartikel (refereegranskat)abstract
- Cytochrome c oxidase (CytcO), the final electron acceptor in the respiratory chain, catalyzes the reduction of O2 to H2O while simultaneously pumping protons across the inner mitochondrial or bacterial membrane to maintain a transmembrane electrochemical gradient that drives, for example, ATP synthesis. In this work mutations that were predicted to alter proton translocation and enzyme activity in preliminary computational studies are characterized with extensive experimental and computational analysis. The mutations were introduced in the D pathway, one of two proton-uptake pathways, in CytcO from Rhodobacter sphaeroides. Serine residues 200 and 201, which are hydrogen-bonded to crystallographically resolved water molecules halfway up the D pathway, were replaced by more bulky hydrophobic residues (Ser200Ile, Ser200Val/Ser201Val, and Ser200Val/Ser201Tyr) to query the effects of changing the local structure on enzyme activity as well as proton uptake, release, and intermediate transitions. In addition, the effects of these mutations on internal proton transfer were investigated by blocking proton uptake at the pathway entrance (Asp132Asn replacement in addition to the above-mentioned mutations). Even though the overall activities of all mutant CytcO's were lowered, both the Ser200Ile and Ser200Val/Ser201Val variants maintained the ability to pump protons. The lowered activities were shown to be due to slowed oxidation kinetics during the PR → F and F → O transitions (PR is the "peroxy" intermediate formed at the catalytic site upon reaction of the four-electron-reduced CytcO with O2, F is the oxoferryl intermediate, and O is the fully oxidized CytcO). Furthermore, the PR → F transition is shown to be essentially pH independent up to pH 12 (i.e., the apparent pKa of Glu286 is increased from 9.4 by at least 3 pKa units) in the Ser200Val/Ser201Val mutant. Explicit simulations of proton transport in the mutated enzymes revealed that the solvation dynamics can cause intriguing energetic consequences and hence provide mechanistic insights that would never be detected in static structures or simulations of the system with fixed protonation states (i.e., lacking explicit proton transport). The results are discussed in terms of the proton-pumping mechanism of CytcO.
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| 2. |
- Lepp, M, et al.
(författare)
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Learning Through Drama in the Field of Global Nursing
- 2011
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Ingår i: Applied Theatre Researcher. - : The Center for Applied Theatre Researcher. - 1443-1726. ; :12, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- This article explores how nurses (nurse educators, and doctoral and masters students) from three countries experienced learning through drama in the field of nursing education. In this era of internationalisation, there is an urgent need to prepare nurses with global perspectives. This qualitative study builds on the fourteen participants’ involvement in a drama workshop and their related reflective journals, which were the subject of a quality content analysis. Two categories and five sub-categories emerged in the analysis of the participants’ journals. This study has implications for nursing education and curriculum activities in nursing programs related to the preparation of nurses with a global perspective using drama as core pedagogy. Through drama, participants can access their lifeworlds and share them with one another. Drama makes the experience-based knowledge visible, and in addition develops knowledge about a certain topic depending on the group’s background and contribution.
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| 3. |
- Lundén, Maud, 1959, et al.
(författare)
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Patients´experiences and feelings before undergoing peripheral transluminal angioplasty
- 2013
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Ingår i: Journal of Vascular Nursing. - : Elsevier BV. - 1062-0303. ; 31:4, s. 158-164
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Tidskriftsartikel (refereegranskat)abstract
- The use of interventional radiology as treatment has increased dramatically and peripheral arterial disease (PAD) is now a common indication for vascular interventions such as percutaneous transluminal angioplasty (PTA).1 PAD seriously impairs quality of life, and patients experience a lack of control over the disease. The aim of this study was to identify patients who are predominantly anxious or calm before PTA treatment and to explore reasons for these feelings. The study includes both individual interviews, a shortened version of a Swedish Mood Adjective Check List (MACL), and an overall assessment of the perceived degree of calmness–anxiety. Forty-two patients were included in the study. The ‘anxious’ group showed a significantly lower mood in all scales of the MACL compared with the ‘calm’ group. Reasons for feeling calm were a sense of being safe and high expectations. Reasons for feeling anxious were represented by a sense of despair and apprehension about the PTA. The main reason for feeling calm was related to trust in their caregivers and an ability to foresee upcoming events. The main reason for feeling anxious before the PTA was fear of a negative outcome and being unsure of treatment options. Greater knowledge and a better understanding of their disease and treatment options would support patients’ ability to accept reasons for waiting before using invasive treatment. Moreover, this could decrease their anxiety and increase their feeling of being in control of their situation.
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| 4. |
- Lundén, Maud, 1959, et al.
(författare)
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The Nurse Radiographers´ Experience of Meeting with Patients During Interventional Radiology : Nurse Radiographers´Experience During IR
- 2012
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Ingår i: Journal of Radiology Nursing. - : Elsevier BV. - 1546-0843. ; 31:2, s. 53-61
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: A wide range is carried out in catheterization laboratories in radiological departments everyday. In Sweden, the nurse radiographers are usually responsible for patient care, medical technical equipment, and sterility during interventional radiology. The competence of a nurse radiographer is mainly equated with that of registered nurses. The aim of this qualitative study was to describe nurse radiographers’ experiences of caring for patients undergoing radiological interventions at the catheterization laboratories. The study is based on individual interviews analyzed using a hermeneutic approach. “Sensing and responding to the patient” was the main theme that appeared in this study from the radiographers’ descriptions of their encounters with patients undergoing radiological intervention. The meaning of this main theme is based on four themes; creating a trusting atmosphere, creating a dialogue, dealing with unpredictable outcomes, and dealing with pain and agony. (J Radiol Nurs 2012;31:53-61.) KEYWORDS: Experience; Nurse radiographer; Hermeneutic.
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