| 1. |
- Greiff, Lennart, et al.
(författare)
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Effects of hydrogen peroxide on the guinea-pig tracheobronchial mucosa in vivo
- 1999
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Ingår i: Acta Physiologica Scandinavica. - : Wiley. - 0001-6772 .- 1365-201X. ; 165:4, s. 415-420
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Tidskriftsartikel (refereegranskat)abstract
- Lumenal entry of plasma (mucosal exudation) is a key feature of airway inflammation. In airways challenged with histamine-type mediators and allergen the mucosal exudation response occurs without causing epithelial derangement and without increased airway absorption. In contrast, reactive oxygen metabolites may cause mucosal damage. In this study, involving guinea-pig airways, we have examined effects of H2O2 on airway exudation and absorption in vivo. Vehicle or H2O2 (0.1 and 0.5 M) was superfused onto the tracheobronchial mucosal surface through an oro-tracheal catheter. 125I-albumin, given intravenously, was determined in tracheobronchial tissue and in lavage fluids 10 min after challenge as an index of mucosal exudation of plasma. The tracheobronchial mucosa was also examined by scanning electron microscopy. In separate animals, 99mTc-DTPA was superfused 20 min after vehicle or H2O2 (0.1 and 0.5 M) had been given. A gamma camera determined the disappearance rate of 99mTc-DTPA from the airways as an index of airway absorption. The high dose of H2O2 (0.5 M) produced epithelial damage, increased the absorption of 99mTc-DTPA (P < 0.001), and increased the exudation of plasma (P < 0.001). Notably, it appeared that all extravasated plasma had entered the airway lumen within 10 min. These data demonstrate that H2O2 differs from exudative autacoids such as histamine by causing both epithelial damage and plasma exudation responses. These data also agree with the view that the epithelial lining determines the rate of absorption and is responsible for the valve-like function that allows lumenal entry of extravasated bulk plasma without any increased inward perviousness.
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| 2. |
- Greiff, Lennart, et al.
(författare)
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Effects of topical platelet activating factor on the guinea-pig tracheobronchial mucosa in vivo
- 1997
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 160:4, s. 387-391
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Tidskriftsartikel (refereegranskat)abstract
- Platelet activating factor (PAF) has been reported to produce a variety of airway effects including epithelial damage and increased airway-lung absorption of hydrophilic tracers. The present study examines effects of PAF on the guinea-pig tracheobronchial mucosa in vivo. Vehicle with and without PAF (4.0 and 8.0 nmol) was superfused onto the tracheobronchial mucosa. The levels of 125I-albumin, previously given intravenously, were determined in tracheobronchial lavage fluids as an index of mucosal exudation of plasma. The mucosa was also examined by scanning electron microscopy. In separate animals, 99mTc-DTPA (a low molecular weight, 492 Da, hydrophilic tracer) was superfused onto the mucosal surface through an oro-tracheal catheter, together with vehicle or PAF (8.0 nmol). A gamma camera determined the disappearance rate of 99mTc-DTPA from the airways as an index of mucosal absorption. PAF produced dose-dependent mucosal exudation of plasma up to 20-fold greater than control (P < 0.001). However, PAF did not damage the epithelium and the absorption ability of the airway mucosa was unaffected. The results, in contrast to previous reports, suggest that PAF may not readily damage the airway mucosa even at large exudative doses of the agent. The present finding support the view that the plasticity of the epithelial junctions allows the creation of valve-like paracellular pathways for unidirectional clearance of extravasated plasma into the airway lumen. We suggest that endogenous PAF may participate in first line respiratory defence reactions by causing lumenal entry of bulk plasma without harming the epithelium.
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| 3. |
- Persson, Carl, et al.
(författare)
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Airway permeability
- 1995
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Ingår i: Clinical and Experimental Allergy. - : Wiley. - 1365-2222. ; 25:9, s. 807-814
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Forskningsöversikt (refereegranskat)
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| 4. |
- Rydén Ahlgren, Åsa, et al.
(författare)
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Increased aortic stiffness in women with type 1 diabetes mellitus is associated with diabetes duration and autonomic nerve function
- 1999
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Ingår i: Diabetic Medicine. - 1464-5491. ; 16:4, s. 291-297
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: The increase in risk for cardiovascular complications in diabetic women is even greater than that in diabetic men. We found arterial stiffness to be increased in women, but not in men, with Type 1 diabetes mellitus (DM). The aims of the present study were to evaluate whether the changes in arterial distensibility are influenced by diabetes duration and to evaluate any association between autonomic neuropathy and decreased arterial distensibility. METHODS: Stiffness of the abdominal aorta was measured noninvasively using echo-tracking sonography and parasympathetic function by heart rate variation during deep breathing (E/I ratio) in 40 women (mean age 33 years, range 20-61) and 38 men (mean age 36 years, range 22-56) with Type 1 DM. RESULTS: There was a significant correlation between aortic stiffness and duration of diabetes in women (r = 0.41, P = 0.008), but not in men (r = 0.15, P = 0.35). There was also a significant correlation between aortic stiffness and the E/I ratio in women (r = -0.49, P = 0.002), but not in men (r = -0.14, P = 0.41). When adjusted for diabetes duration, the significant association between the E/I ratio and aortic stiffness remained in diabetic women (r = -0.44, P = 0.008) and was stronger than the association between diabetes duration and aortic stiffness. There were no significant correlations between aortic stiffness and triglycerides or total cholesterol, respectively. CONCLUSIONS: Increased aortic wall stiffness found in women with Type 1 DM is related to diabetes duration. Further, in women with Type 1 DM there is a correlation between increased aortic stiffness and parasympathetic dysfunction. This may be of importance for the increased susceptibility to cardiovascular complications in diabetic women.
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| 5. |
- Rydén Ahlgren, Åsa, et al.
(författare)
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Increased arterial stiffness in women, but not in men, with IDDM
- 1995
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Ingår i: Diabetologia. - 1432-0428. ; 38:9, s. 1082-1089
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Tidskriftsartikel (refereegranskat)abstract
- For unknown reasons, there is a greater increase in the risk for cardiovascular complications in diabetic women than in diabetic men. Our aim was to study gender-related differences in the mechanical properties of the great arteries in patients with insulin-dependent diabetes mellitus (IDDM) but free from known cardiovascular and cerebrovascular complications. We measured arterial stiffness (beta, inversely related to arterial compliance) in the abdominal aorta and the common carotid artery non-invasively using echo-tracking sonography in 30 women (mean age 34 years, range 20-61) and 26 men (mean age 38 years, range 22-56) with IDDM. The results were compared with those of healthy individuals of corresponding age and gender. The results showed a marked gender-difference in changes of arterial stiffness. Arterial stiffness was increased in both the abdominal aorta and the common carotid artery in diabetic women compared to control women (p = 0.0001 and p = 0.0076, respectively). In contrast, there was no significant difference in stiffness of the abdominal aorta or the common carotid artery between the diabetic men and the control men (p = 0.69 and p = 0.39, respectively). In conclusion, this study has shown that stiffness of the aorta and the common carotid artery is increased in diabetic women but not in diabetic men. Increased arterial stiffness in diabetic women may be a pathogenic factor which could help to explain the gender-related differences in the risk for cardiovascular and cerebrovascular complications in diabetic subjects.
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