| 1. |
- Jaworowski, Åsa, et al.
(författare)
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Calponin reduces shortening velocity in skinned taenia coli smooth muscle fibres
- 1995
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Ingår i: FEBS Letters. - 1873-3468. ; 365:2-3, s. 167-171
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Tidskriftsartikel (refereegranskat)abstract
- Calponin (4.1-5.9 microM, pig stomach) inhibited maximal shortening velocity (Vmax) by 20-25% with only minor influence on force in skinned smooth muscle from guinea-pig taenia coli activated at different Ca2+ levels and with thiophosphorylation. Similar results were obtained with a fragment of the N-terminal 1-228 amino acids engineered using a mouse cDNA construct (5.4 microM). Both the native calponin and the fragment inhibited actin filament sliding in a graded manner in an in vitro motility assay. We conclude that calponin influences the kinetics of the actin-myosin interaction in the organised smooth muscle contractile system and that engineered fragments of calponin can be used to probe its action in muscle fibres. The effects can be due to an introduction of an internal load during filament sliding, possibly by decreasing the detachment rates and increasing the cross-bridge time spent in the attached state.
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| 2. |
- Johan, Katarzyna, et al.
(författare)
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Acceleration of amyloid protein A amyloidosis by amyloid-like synthetic fibrils
- 1998
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 0027-8424 .- 1091-6490. ; 95:5, s. 2558-2563
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid protein A (AA) amyloidosis is a consequence of some long-standing inflammatory conditions, and subsequently, an N-terminal fragment of the acute phase protein serum AA forms β-sheet fibrils that are deposited in different tissues. It is unknown why only some individuals develop AA amyloidosis. In the mouse model, AA amyloidosis develops after ≈25 days of inflammatory challenge. This lag phase can be shortened dramatically by administration of a small amount of amyloid extract containing an as yet undefined amyloid-enhancing factor. In the present study, we show that preformed amyloid-like fibrils made from short synthetic peptides corresponding to parts of several different amyloid fibril proteins exert amyloidogenic enhancing activity when given i.v. to mice at the induction of inflammation. We followed i.v. administered, radiolabeled, heterologous, synthetic fibrils to the lung and to the perifollicular area in the spleen and found that new AA–amyloid fibrils developed on these preformed fibrils. Our findings thus show that preformed, synthetic, amyloid-like fibrils have an in vivo nidus activity and that amyloid-enhancing activity may occur, at least in part, through this mechanism. Our findings also show that fibrils of a heterologous chemical nature exert amyloid-enhancing activity.
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| 3. |
- Westrin, Åsa, et al.
(författare)
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Correlations between plasma-neuropeptides and temperament dimensions differ between suicidal patients and healthy controls
- 1998
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Ingår i: Journal of Affective Disorders. - 1573-2517. ; 49:1, s. 45-54
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Decreased plasma levels of plasma-neuropeptide Y (NPY) and plasma-corticotropin releasing hormone (CRH), and increased levels of plasma delta-sleep inducing peptide (DSIP) in suicide attempters with mood disorders have previously been observed. This study was performed in order to further understand the clinical relevance of these findings. METHODS: Examination of correlates between temperament dimensions (Karolinska Scales of Personality (KSP), the Eysenck Personality Questionnaire together with the IVE- impulsiveness scale (EPQI), and the Marke-Nyman Temperament (MNT)) and NPY, CRH and DSIP and serum-cortisol in the dexamethasone suppression test (DST) in 38 suicidal patients and matched controls. RESULTS: NPY correlated significantly and positively with psychasthenia, irritability, and stability and significantly and negatively with validity in patients, but significantly and negatively with muscular tension, psychasthenia, verbal aggression and irritability in controls. DSIP correlated significantly and positively with impulsiveness (EPQI) in controls. CRH correlated negatively with lie in controls. Cortisol correlated significantly and positively with validity, extraversion and verbal aggression and significantly and negatively with inhibition of aggression in controls. CONCLUSION: NPY may be related to stress tolerance. DSIP seems to be associated with impulsivity/antisocial traits. LIMITATIONS: Non-suicidal patients were not included in the examination. CLINICAL RELEVANCE: The state of depression or stress seems to influence the correlations studied.
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