| 1. |
- Lindfors, Charlotte, et al.
(författare)
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Hypothalamic mitochondrial dysfunction associated with anorexia in the anx/anx mouse
- 2011
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 108:44, s. 18108-18113
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Tidskriftsartikel (refereegranskat)abstract
- The anorectic anx/anx mouse exhibits disturbed feeding behavior and aberrances, including neurodegeneration, in peptidergic neurons in the appetite regulating hypothalamic arcuate nucleus. Poor feeding in infants, as well as neurodegeneration, are common phenotypes in human disorders caused by dysfunction of the mitochondrial oxidative phosphorylation system (OXPHOS). We therefore hypothesized that the anorexia and degenerative phenotypes in the anx/anx mouse could be related to defects in the OXPHOS. In this study, we found reduced efficiency of hypothalamic OXPHOS complex I assembly and activity in the anx/anx mouse. We also recorded signs of increased oxidative stress in anx/anx hypothalamus, possibly as an effect of the decreased hypothalamic levels of fully assembled complex I, that were demonstrated by native Western blots. Furthermore, the Ndufaf1 gene, encoding a complex I assembly factor, was genetically mapped to the anx interval and found to be down-regulated in anx/anx mice. These results suggest that the anorexia and hypothalamic neurodegeneration of the anx/anx mouse are associated with dysfunction of mitochondrial complex I.
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| 2. |
- Gustafsson, J., et al.
(författare)
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Motor-Learning-Based Adjustment of Ambulatory Feedback on Vocal Loudness for Patients With Parkinson's Disease
- 2016
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Ingår i: Journal of Voice. - : Elsevier. - 0892-1997 .- 1873-4588. ; 30:4, s. 407-415
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate how the direct biofeedback on vocal loudness administered with a portable voice accumulator (VoxLog) should be configured, to facilitate an optimal learning outcome for individuals with Parkinson's disease (PD), on the basis of principles of motor learning. Study Design: Methodologic development in an experimental study. Methods: The portable voice accumulator VoxLog was worn by 20 participants with PD during habitual speech during semistructured conversations. Six different biofeedback configurations were used, in random order, to study which configuration resulted in a feedback frequency closest to 20% as recommended on the basis of previous studies. Results: Activation of feedback when the wearer speaks below a threshold level of 3dB below the speaker's mean voice sound level in habitual speech combined with an activation time of 500ms resulted in a mean feedback frequency of 21.2%. Conclusions: Settings regarding threshold and activation time based on the results from this study are recommended to achieve an optimal learning outcome when administering biofeedback on vocal loudness for individuals with PD using portable voice accumulators.
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| 3. |
- Schalling, E., et al.
(författare)
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Effects of tactile biofeedback by a portable voice accumulator on voice intensity in speakers with Parkinson’s disease
- 2013
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Ingår i: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588. ; 27:6, s. 729-737
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To study the effects of biofeedback on voice sound level (SL) in subjects with reduced voice SL, secondary to Parkinson disease (PD), using a portable voice accumulator. Study Design: Prospective intervention study. Methods: Voice SL, phonation time, and level of background noise were registered with a portable voice accumulator during three consecutive registration periods. Six subjects with reduced voice SL secondary to PD participated. Biofeedback, in the form of a vibration signal when voice SL went below an individually set threshold level, was administered during the second registration period only. Mean voice SL was calculated for registration periods with and without feedback. Data on phonation time and level of background noise was also collected. Field registrations with the portable voice accumulator were also compared with registrations made in a recording studio. In addition, subjects were asked about subjective experiences of using the portable voice accumulator for up to 15 days. Results: There was a statistically significant increase in voice SL during the period when biofeedback of voice SL was administered. Subjects reported that using the portable voice accumulator was a positive experience. Several participants wished to continue using the device. In general, subjects handled the device independently with no major problems and did not report any negative experiences. Conclusions: Although this study was a first trial including six subjects with reduced voice SL secondary to PD, the findings indicate that biofeedback of voice SL administered via a portable voice accumulator may be a useful treatment tool for this group of patients and that further studies are needed.
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