| 1. |
- Blomqvist, S, et al.
(författare)
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Early post-traumatic changes in hemodynamics and pulmonary ventilation in alcohol-pretreated pigs
- 1987
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Ingår i: Journal of Trauma. - 0022-5282. ; 27:1, s. 40-44
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Tidskriftsartikel (refereegranskat)abstract
- Time relations among trauma, pulmonary and systemic circulation, and lung function were studied in pigs. Eleven animals (b.w. 25-30 kg) were investigated under balanced anesthesia. Ventilation was mechanically controlled. Hemodynamics, pulmonary ventilation, and gas exchange were serially recorded. Seven animals were pretreated with 40% ethanol in saline and four with saline only. Ninety minutes after the ingestion of alcohol or saline, the animals were subjected to a standardized soft-tissue trauma. Cardiac output decreased significantly 2 minutes after trauma and remained low in both groups throughout the observation period of 30 minutes. Pulmonary vascular resistance was significantly increased in the alcohol-pretreated group but was virtually unchanged in the control animals. Systemic vascular resistance was similarly reduced in the two groups. Total compliance was somewhat lower in alcohol-pretreated animals and 10 minutes after the trauma arterial oxygen tension was significantly lower in the alcohol group than in control animals. Carbon dioxide elimination was reduced after trauma in both groups. It is concluded that pulmonary vascular response increased and that total pulmonary compliance is somewhat decreased shortly after trauma in the alcohol group while gas exchange is almost unchanged. The results indicate a negative interaction between alcohol and trauma
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| 2. |
- Elmér, Olle, et al.
(författare)
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Prevention of posttraumatic pulmonary platelet trapping by portacaval transposition
- 1988
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Ingår i: The American Journal of Surgery. - 1879-1883. ; 155:2, s. 289-292
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Tidskriftsartikel (refereegranskat)abstract
- Significant soft-tissue trauma induces platelet activation, aggregation, and sequestration in the lungs. This pulmonary trapping is due either to the size of the platelet aggregates or to changes in the pulmonary microvasculature. To evaluate which one of these mechanisms is responsible for the trapping, we performed portacaval transposition in one group of pigs, making the liver the first receiving capillary bed for blood from the trauma sites in the lower extremities. One week after the operation, the platelets were labeled with indium oxine and reinfused, and the operated animals and a group of six control animals were subjected to standardized soft-tissue trauma to the lower extremities. Sequestration of platelets in the lungs and in the liver was registered dynamically before and for 90 minutes after the trauma. Soft-tissue trauma induced platelet sequestration in the liver in the operated group (p less than 0.01) and in the lungs in the control group (p less than 0.01). Trapping was paralleled by a decrease in the number of circulating platelets. This study has indicated that posttraumatic pulmonary platelet trapping is caused by platelet activation at the trauma sites and not by changes in the pulmonary microvasculature.
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| 3. |
- Pärsson, H, et al.
(författare)
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Experimental evaluation of small diameter synthetic arterial grafts
- 1988
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Ingår i: International Angiology. - 1827-1839. ; 7:1, s. 60-64
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Tidskriftsartikel (refereegranskat)abstract
- Platelets labelled with Indium-111 were used to examine the in vivo thrombogenicity of different vascular grafts. The deposition of platelets in two partly different kinds of umbilical vein grafts, double velour Dacron grafts and double velour Dacron grafts with internal collagen was studied as a function of time. The grafts were inserted end to side in the femoral artery of pigs and then imaged for 120 minutes. Platelet distribution was also studied by in vitro static imaging. No difference was seen between the different umbilical vein grafts. The double velour grafts accumulated more platelets, the platelets mainly located in the midportion of the graft. The collagen-impregnated grafts occluded within 45 minutes
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| 4. |
- Ribbe, Else, et al.
(författare)
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Platelet aggregation on peritoneal tube grafts and double velour grafts in the inferior vena cava of the pig
- 1988
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Ingår i: British Journal of Surgery. - : Oxford University Press (OUP). - 1365-2168 .- 0007-1323. ; 75:1, s. 81-85
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Tidskriftsartikel (refereegranskat)abstract
- In 14 pigs the infrarenal vena cava was replaced with a peritoneal tube graft or a collagen-coated double velour graft. With 111In-labelled platelets dynamic in vivo imaging of platelet aggregation over the graft was carried out using a scintillation camera. After removal, the grafts were examined by autoradiography for an evaluation of the platelet aggregation pattern. Measurements of activity in different regions of the grafts were also performed. The results indicated low activity uptakes both in vivo and in vitro. The dynamic study did not show any uniform increase of activity content 1-3 h postoperatively, in any of the groups. During the period 2-3 h postoperatively no increasing activity accumulation was found. Hemashield Microvel grafts had an uptake of 0.19 per cent of the total activity while the corresponding figure for peritoneal tube grafts was 0.17 per cent. The activity distribution on different parts of the grafts indicated lower accumulation on the Hemashield graft surfaces than in the anastomoses, while the accumulation was higher on the graft surface of peritoneal tube grafts. The autoradiographical findings supported this indication. In conclusion, low platelet aggregation was found with both dynamic in vivo imaging and in vitro activity measurements on both peritoneal tube grafts and collagen-coated double velour grafts.
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| 5. |
- Svensson, Henry, et al.
(författare)
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Laser Doppler flowmetry during hyperaemic reactions in the skin
- 1988
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Ingår i: International journal of microcirculation, clinical and experimental. - 0167-6865. ; 7:1, s. 87-96
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Tidskriftsartikel (refereegranskat)abstract
- Laser Doppler flowmetry (LDF) was used to study skin blood flow in the finger tip and on the dorsum of the hand in healthy volunteers. Vasodilatation in the finger tip was induced by immersing the arm in water at 42 degrees C, and vasodilatation in the dorsum of the hand by intracutaneous injection of dihydralazine. Simultaneous measurements were performed using venous occlusion plethysmography (finger tip) and 133Xe clearance (dorsum of hand). Three output signals from the laser Doppler flowmeter were recorded. The LDFPf-1 value is linearly related to the blood flow, provided the concentration of blood cells in the scattering volume is low. The LDFPf-2 value is generated by a signal processor designed to give linearity even at higher concentrations of moving blood cells (CMBC), the latter quantity being reflected by the CMBC value. During vasodilatation by immersion, all laser Doppler values from the finger tip increased but less than the total finger blood flow as measured using venous occlusion plethysmography. Intracutaneous injection of dihydralazine in the dorsum of the hand caused markedly increased CMBC values and the increase in LDFPf-2 was significantly greater than that of LDFPf-1. The increase in 133Xe clearance was less pronounced. The results indicate that capillary blood flow as well as blood flow in vessels below the capillary level contribute to the Doppler signal. However, flow through the arteriovenous shunts in the finger tip seems to be only partially registered by the laser Doppler technique. The higher the CMBC value, the more obvious is the difference between LDFPf-1 and LDFPf-2 values. When using laser Doppler flowmetry, the addition of CMBC value registration may be helpful in clarifying changes in microvascular blood flow.
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| 6. |
- Thörne, Johan, et al.
(författare)
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Early posttraumatic pulmonary platelet trapping and its potentiation by oral pretreatment with alcohol
- 1986
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Ingår i: The American Journal of Surgery. - : Elsevier BV. - 1879-1883 .- 0002-9610. ; 151:2, s. 216-220
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Tidskriftsartikel (refereegranskat)abstract
- Soft tissue trauma is associated with platelet aggregation and sequestration in the lungs. This is believed to be an early step in the later development of adult respiratory distress syndrome. In the present experiment using a new method for in vivo dynamic studies of platelet sequestration, we wanted to evaluate the effect of soft tissue trauma on pulmonary platelet trapping in pigs and the influence of acute alcohol intoxication. The results show that significant pulmonary platelet trapping is registered within minutes of trauma and that alcohol significantly increases platelet sequestration in the lungs. This indicates an increased risk for posttraumatic pulmonary problems in alcohol-intoxicated trauma victims
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| 7. |
- Thörne, Johan, et al.
(författare)
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Effect of ticlopidine and prostaglandin E on endotoxin-induced pulmonary platelet sequestration in vivo
- 1986
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Ingår i: Circulatory Shock. - 0092-6213. ; 20:1, s. 61-69
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Tidskriftsartikel (refereegranskat)abstract
- Prostaglandin E1 has earlier been shown to decrease pulmonary platelet trapping (PPT) following shock. This experiment was performed to evaluate a new method to study PPT in vivo, and to study the effect of prostaglandin E1 and a new antiplatelet drug (ticlopidine) on PPT in rabbits after i.v. administration of endotoxin. Following platelet labeling with In-111, the rabbits were placed under a scintillation camera for continuous measuring of the activity distribution for 40 minutes. The first five minutes represented reference values, whereafter endotoxin E. coli was injected i.v. The following 2-4 minutes showed a sudden increase of radioactivity over the lungs and a simultaneous decrease over the heart, indicating PPT in the nontreated animals, followed by a slow decrease to almost preshock values during the following 30 minutes. Animals receiving prostaglandin E1 showed a significantly lower activity peak in the lungs after the administration of endotoxin, while the corresponding peak in ticlopidine-treated animals did not differ from that seen in the nontreated animals. In all groups, endotoxin caused a decrease in platelet count, but it was significantly lower in the PGE1-treated animals. The results have shown that this diagnostic model for PPT is reliable and may be used for evaluation of the effect on platelet aggregation in vivo of different drugs
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| 8. |
- Widner, Håkan, et al.
(författare)
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Scintigraphic method to quantify the passage from brain parenchyma to the deep cervical lymph nodes in rats
- 1987
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - 1619-7070. ; 13:9, s. 456-461
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Tidskriftsartikel (refereegranskat)abstract
- In order to investigate the kinetics of the passage from the brain parenchyma to the lymphatic system in vivo a high resolution scintillation camera technique was developed. Albumin, albumin colloids and dextran labelled with 99mTc were injected into the right side of the thalamus of anesthetized rats. Continuous measurement of the activity distribution in head and neck were performed for 70 min. Rate constants were calculated by means of a computer program for compartment analysis. The animals were killed 10 h postinjection, to measure the activity in tissue samples. For some animals, images were registered up to 24 h after injection. This work presents an in vivo technique to clarify the particle flow paths in the brain and make quantification possible. The method is simple and does not require continuous blood or lymph sampling. Our work shows that there is a substantial flow of injected material from the brain via lamina cribriformis to the lymphatic system. This route is of great interest for the drainage of the interstitial fluid of the brain. We have also shown a difference in flow for dextran particles with different charge
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