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- Augustsson, Olga, et al.
(författare)
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The Johanneberg Study: a Social Survey in an Urban Elderly Population. I. General presentation of the study including an analysis of non-response and identification of risk groups
- 1993
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Ingår i: Scandinavian Journal of Social Medicin. ; 22:4, s. 283-92
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Tidskriftsartikel (refereegranskat)abstract
- This study is the Swedish part of a world-wide transcultural and interdisciplinary study in elderly populations which addresses food habits, health and life-style. The aim of this paper is to present the general design including an analysis of non-response, and to identify risk-groups for intervention programmes. The study comprised 217 noninstitutionalized males (n = 73) and females (n = 144), aged 70 and over (mean age 78 years) in a small urban area. Home visits and clinical examinations with standard methods were used. The participation rate was 76%. Significant differences between non-respondents and respondents could be seen, which may be important when planning health promotion. On the basis of experience during the examinations, a risk-group was identified for prospective and intervention study purpose, based on a multiple variable model and a clinical model.
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| 5. |
- Kimblad, Per Ola, et al.
(författare)
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Endothelium-dependent relaxation in pulmonary arteries after lung preservation and transplantation
- 1993
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 56:6, s. 1329-1333
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Tidskriftsartikel (refereegranskat)abstract
- Pulmonary hypertension is frequently seen after lung transplantation. To study how the release of the endothelium-dependent relaxing factor is affected by lung preservation and transplantation, porcine pulmonary arteries were investigated in organ baths. The arteries (1 mm in diameter) were taken from fresh nonperfused lungs (group I), lungs immediately after flush-perfusion with a low-potassium-dextran solution (group II), non-perfused lungs stored for 12 hours in low-potassium-dextran solution (group III), flush-perfused lungs stored for 12 hours in low-potassium-dextran solution (group IV), and group IV lungs after left lung transplantation and right pneumonectomy followed by 24 hours of reperfusion (group V). Stable contractions were induced with the thromboxane A2 analogue U-46619. Acetylcholine was used to stimulate the release of endothelium-dependent relaxing factor. In vessel segments where the endothelium had been removed, acetylcholine elicited no response. In segments with intact endothelium, acetylcholine induced concentration-dependent relaxation; the maximum relaxation obtained was 91% +/- 3% (I), 86% +/- 3% (II), 85% +/- 3% (III), 69% +/- 5% (IV), and 69% +/- 9% (V). Relaxation was significantly reduced in groups IV (p < 0.01) and V (p < 0.05) as compared with group I. Stable moderate pulmonary hypertension was present in all the transplanted lungs throughout the 24-hour observation period. It is concluded that the endothelium-mediated relaxation is significantly reduced after flush perfusion combined with 12 hours of storage in low-potassium-dextran solution. Lung transplantation, followed by 24 hours of reperfusion did not further impair the endothelium-dependent relaxation.
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| 6. |
- Kimblad, Per Ola, et al.
(författare)
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High potassium contents in organ preservation solutions cause strong pulmonary vasocontraction
- 1991
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 52:3, s. 523-528
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Tidskriftsartikel (refereegranskat)abstract
- Euro-Collins (ECS) and UCLA-formula organ preservation solutions induced strong vasocontraction in porcine pulmonary arteries when studied in organ baths at temperatures of 37 degrees C and 30 degrees C. At 20 degrees C ECS induced a 30% contraction, but at 6 degrees C no contraction (n = 5) or a weak contraction (n = 1) was elicited. Neither prostaglandin E1 nor nifedipine caused any significant reduction of the vasocontraction elicited by ECS and UCLA. Krebs solution, enriched with potassium in amounts corresponding to those in ECS (115 mmol/L) or UCLA (30 mmol/L), induced vasocontraction comparing well with those induced by ECS or UCLA, indicating that it is the high potassium content that causes the vasocontraction. In a second experiment lung segments were stored at 4 degrees C for 9 hours in ECS, UCLA, or Krebs solution. Pulmonary arterial segments were then studied in organ baths at 37 degrees C. The choice of preservation solution did not significantly affect the contractile properties of potassium, noradrenaline, or the thromboxane mimic U-46619. To conclude, high potassium contents in organ preservation solutions induce strong pulmonary vasocontraction in lung temperatures greater than 20 degrees C but not in temperatures less than 10 degrees C. These vasocontractions are not significantly reduced by prostaglandin E1 or nifedipine. We suggest that the initial preservation solution used to cool down the lungs should contain 4 mmol/L or no potassium. When the lung temperature is less than 10 degrees C, a second perfusion might be done, and then a high potassium content (if thought to be essential) will not cause vasocontraction.
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| 7. |
- Massa, G, et al.
(författare)
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Endothelium-dependent relaxation after short-term preservation of vascular grafts
- 1994
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 58:4, s. 1117-1122
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Tidskriftsartikel (refereegranskat)abstract
- As the integrity of graft endothelium seems to be essential to successful long-term patency in coronary operations, its preservation demands the utmost care. The aim of the present study was to investigate the effects of currently used solutions on endothelium-dependent relaxation after short-term storage of vessels at room temperature or at 4 degrees C. The infrarenal rat aorta was selected for study because its use enabled standardization of the investigation, which was performed in organ baths on 672 vessel segments from 112 Sprague-Dawley rats. Stable vasoconstriction was obtained with the thromboxane analogue U-46619. Acetylcholine was used to elicit endothelium-dependent relaxation. The results obtained for vessels preserved for 2 hours were compared with those for autologous vessels studied immediately after harvesting. Vessel contractility was unaffected by the preservation solutions, except in the Ringer's acetate group, where it was reduced by 50% (p < 0.05). Endothelium-independent relaxation, tested with papaverine, was unaffected in all groups. Ringer's lactate, Krebs solution, and Perfadex (a low-potassium-dextran-glucose solution) did not significantly affect endothelium-dependent relaxation either at room temperature or at 4 degrees C, although a tendency to impaired relaxation was seen in these three groups after cold storage. Standard Ringer's solution and fresh heparinized blood each significantly reduced endothelium-dependent relaxation in vessels stored at room temperature (p < 0.05), but not in those stored at 4 degrees C. Endothelium-dependent relaxation was significantly reduced after storage in normal saline solution (p < 0.05) and in Ringer's acetate (p < 0.01), both at room temperature and at 4 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 8. |
- Massa, G, et al.
(författare)
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Might free arterial grafts fail due to spasm?
- 1991
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 51:1, s. 94-101
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Tidskriftsartikel (refereegranskat)abstract
- The rat femoral artery was used as a free graft and was studied after 2, 7, 14, 30, and 60 days. The patency of the grafts was 100% (2 days, n = 6), 78% (7 days, n = 9), 63% (14 days, n = 8), 33% (30 days, n = 12), and 18% (60 days, n = 11). Histology showed an intimal thickening after 14 days and the media, which in the controls consisted of eight to ten layers of myocytes, was reduced to six to eight cell layers. During the first 2 weeks the graft segments had an impaired contraction when exposed to Krebs solution with 124 mmol/L K+, whereas after 1 month and later the graft segments approached the controls or had even higher contractile force. The thromboxane mimic U-46619 elicited full contractile force at all times whereas the potency was significantly lower during the first 14 days. Noradrenaline was unable to induce contraction in the graft segments during the first 14 days, but at 30 and 60 days it had regained full contractile force and was significantly more potent (approximately 60 times) in the graft segments compared with the controls. This study suggests that intimal thickening and hypercontractility might be a problem in free muscular arterial grafts.
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| 9. |
- Sjöberg, Trygve, et al.
(författare)
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Endothelium-mediated relaxation in transplanted aorta
- 1992
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 53:6, s. 1068-1073
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Tidskriftsartikel (refereegranskat)abstract
- This study compares the vasodilating effect of endothelium-derived relaxing factors (EDRFs) in free arterial grafts with that in their normal control vessels. The infrarenal aorta of Sprague-Dawley rats was transplanted into the same position in other inbred recipient rats. A Krebs buffer solution (4 degrees C) served as the preservation solution. The ischemic time for the grafts (n = 8) was 42 +/- 1 minutes. Two grafts were studied after 3 days and six grafts, after 60 days. Ring segments were cut from all vessels, and isometric contractions were recorded in organ baths. The vessel segments were constricted with noradrenaline, a thromboxane A2 mimic (U-46619), or prostaglandin F2 alpha. Concentration-response curves with acetylcholine, which was used as the endothelium-stimulating substance causing release of EDRFs, were obtained. The patency of the grafts was 100%. Acetylcholine induced relaxation in all vessel segments with intact intima, whereas no relaxation was seen when the endothelium was manually removed. No significant differences were found between the grafts and the normal control vessels. Histology of the 60-day grafts showed elastomuscular arteries without intimal thickening and a media consisting of eight to ten muscle layers interrupted by five to six elastic lamellae. Scanning electron microscopy showed no major differences between normal endothelium and the endothelium of 3-day or 60-day grafts. This study indicates that free elastomuscular arterial grafts, in which the morphology of the intima is preserved, will retain their full ability to release EDRFs.
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| 10. |
- Steen, Stig, et al.
(författare)
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Safe pulmonary preservation for 12 hours with low-potassium-dextran solution
- 1993
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 55:2, s. 434-440
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Tidskriftsartikel (refereegranskat)abstract
- The function of porcine left lung allografts was studied after perfusion with (150 mL/kg) and storage for 12 hours in a 4 degrees to 6 degrees C low-potassium-dextran solution (Perfadex; Kabi Pharmacia AB, Uppsala, Sweden). After a left lung transplantation, an artificial lung in the form of venoarterial extracorporeal membrane oxygenation was established. The artificial lung has a "biological" heparin-coated surface (Carmeda AB, Stockholm, Sweden), and there is no need for systemic anticoagulation. Immediately thereafter, pneumonectomy of the normal right lung was done. All the animals were weaned from the artificial lung within 1 hour after the pneumonectomy. Six animals were followed up for 24 hours. They were in good condition throughout the 24-hour observation period with arterial oxygen tensions around 200 mm Hg (inspired oxygen fraction = 0.4) and arterial carbon dioxide tensions around 40 mm Hg. This study demonstrates a reliable method for continuous evaluation of the function of a transplanted lung immediately after transplantation and over the ensuing postoperative period. Safe 12-hour lung preservation can be obtained with the low-potassium-dextran solution Perfadex.
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