| 1. |
- Basu, Samar, et al.
(författare)
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Propofol mitigates systemic oxidative injury during experimental cardiopulmonary cerebral resuscitation
- 2011
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Ingår i: Prostaglandins, Leukotrienes and Essential Fatty Acids. - : Elsevier BV. - 0952-3278 .- 1532-2823. ; 84:5-6, s. 123-130
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Tidskriftsartikel (refereegranskat)abstract
- Effects of propofol, an intravenous anesthetic agent that exerts potent antioxidant properties, were investigated in an experimental model of cardiac arrest and cardiopulmonary resuscitation. An extended cardiac arrest with 15 randomized piglets was studied to assess the effect of propofol or its solvent intralipid as the control group. Oxidative stress (as measured by a major F(2)-isoprostane) and inflammation (a major metabolite of PGF(2α)) were evaluated in addition to the hemodynamic evaluation, protein S-100β and in situ tissue brain damage by immunochemistry at sacrifice after 3h of reperfusion following cardiac arrest and restoration of spontaneous circulation (ROSC). ROSC increased jugular bulb plasma levels of F(2)-isoprostane and PGF(2α) metabolite significantly more in controls than in the propofol-treated group. In situ tissue damage after ischemia-reperfusion was variable among the pigs at sacrifice, but tended to be greater in the control than the propofol-treated group. Propofol significantly reduced an ROSC-mediated oxidative stress in the brain.
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| 2. |
- Halvorsen, Peter, et al.
(författare)
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Neural injury after use of vasopressin and adrenaline during porcine cardiopulmonary resuscitation
- 2015
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 120:1, s. 11-19
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Tidskriftsartikel (refereegranskat)abstract
- Background. Our aim was to investigate cerebral and cardiac tissue injury subsequent to use of vasopressin and adrenaline in combination compared with vasopressin alone during cardiopulmonary resuscitation (CPR). Methods. In a randomized, prospective, laboratory animal study 28 anesthetized piglets were subject to a 12-min untreated cardiac arrest and subsequent CPR. After 1 min of CPR, 10 of the piglets received 0.4 U/kg of arg(8)-vasopressin (V group), and 10 piglets received 0.4 U/kg of arg(8)-vasopressin, 1 min later followed by 20 mu g/kg body weight of adrenaline, and another 1 min later continuous administration (10 mu g/kg/min) of adrenaline (VA group). After 8 min of CPR, the piglets were defibrillated and monitored for another 3 h. Then they were killed and the brain immediately removed pending histological analysis. Results. During CPR, the VA group had higher mean blood pressure and cerebral cortical blood flow (CCBF) but similar coronary perfusion pressure. After restoration of spontaneous circulation there was no difference in the pressure variables, but CCBF tended to be (36% +/- 16%) higher in the V group. Neuronal injury and signs of a disrupted blood-brain barrier (BBB) were greater, 20% +/- 4% and 21% +/- 4%, respectively, in the VA group. In a background study of repeated single doses of adrenaline every third minute after 5 min arrest but otherwise the same protocol, histological measurements showed even worse neural injury and disruption of the BBB. Conclusion. Combined use of vasopressin and adrenaline caused greater signs of cerebral and cardiac injury than use of vasopressin alone during experimental cardiopulmonary resuscitation.
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| 3. |
- Semenas, Egidijus, et al.
(författare)
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Neuroprotective effects of 17-beta-estradiol after hypovolemic cardiac arrest in immature piglets: the role of nitric oxide and peroxidation
- 2011
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Ingår i: Shock. - 1073-2322 .- 1540-0514. ; 36:1, s. 30-37
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Tidskriftsartikel (refereegranskat)abstract
- We recently reported that cerebral and cardiac injuries are mitigated in immature female piglets after severe hemorrhage with subsequent cardiac arrest (CA) Female sex was also associated with a smaller increase in the cerebral expression of inducible and neuronal nitric oxide synthase (nNOS). In the current study, we tested the hypothesis that exogenously administered 17β-estradiol (E2) can improve neurological outcome by NOS modulation. Thirty nine sexually immature piglets were bled to a mean arterial pressure of 35 mmHg over 15 min. Fifty μg/kg of E2 was then administered to 10 male and 10 female animals (estradiol group), while control animals (n=10 males and 9 females) received equal volume of normal saline. The animals were then subjected to ventricular fibrillation (4 min) followed by up to 15 min of open chest CPR. Vasopressin 0.4 U/kg and amiodarone 0.5 mg/kg were given and 3 ml/kg of 7.5% saline with 6% dextran was administered over 20 min. All surviving animals were euthanized after 3hr and their brains examined for histological injury and NOS expression. No significant differences were observed in survival or hemodynamics between the groups. Compared with the control group, animals in the E2 group exhibited a significantly smaller increase in nNOS and iNOS expression, a smaller blood-brain-barrier disruption and a mitigated neuronal injury. There was a significant correlation between nNOS and iNOS levels and neuronal injury. Interestingly estradiol attenuated cerebral damage (including lower activation of nNOS and iNOS) both in male and female piglets. In conclusion, in our immature piglets model of hypovolemic cardiac arrest, E2 down-regulates iNOS and nNOS expression and results in decreased BBB permeability disruption and smaller neuronal injury.
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| 4. |
- Semenas, Egidijus, et al.
(författare)
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Sex differences in cerebral injury after severe haemorrhage and ventricular fibrillation in pigs
- 2010
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 54:3, s. 343-353
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Tidskriftsartikel (refereegranskat)abstract
- Background: Experimental studies of haemorrhagic shock have documented a superior haemodynamic response and a better outcome in female animals as compared with male controls. Such sexual dimorphism has, nevertheless, not been reported after circulatory arrest that follows exsanguination and shock. We aimed to study differences in cerebral injury markers after exsanguination cardiac arrest in pre-pubertal piglets. The hypothesis was that cerebral injury is less extensive in female animals, and that this difference is independent of sexual hormones or choice of resuscitative fluid. Methods: Thirty-two sexually immature piglets (14 males and 18 females) were subjected to 5 min of haemorrhagic shock followed by 2 min of ventricular fibrillation and 8 min of cardiopulmonary resuscitation, using three resuscitation fluid regimens (whole blood, hypertonic saline and dextran, or acetated Ringers' solution plus whole blood and methylene blue). Haemodynamic values, cellular markers of brain injury and brain histology were studied. Results: After successful resuscitation, female piglets had significantly greater cerebral cortical blood flow, tended to have lower S-100beta values and a lower cerebral oxygen extraction ratio. Besides, in female animals, systemic and cerebral venous acidosis were mitigated. Female piglets exhibited a significantly smaller increase in neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) expression in their cerebral cortex, smaller blood-brain-barrier (BBB) disruption and significantly smaller neuronal injury. Conclusion: After resuscitation from haemorrhagic circulatory arrest, cerebral reperfusion is greater, and BBB permeability and neuronal injury is smaller in female piglets. An increased cerebral cortical iNOS and nNOS expression in males implies a mechanistic relationship with post-resuscitation neuronal injury and warrants further investigation.
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| 5. |
- Wiklund, Lars, et al.
(författare)
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Circulatory arrest as a model for studies of global ischemic injury and neuroprotection
- 2005
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Ingår i: Annals of the New York Academy of Sciences. - : Wiley. - 0077-8923 .- 1749-6632. ; 1053, s. 205-219
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Tidskriftsartikel (refereegranskat)abstract
- Despite many programs aimed at better immediate care of cardiac arrest victims, the subsequent mortality rate is high, with myocardial and central nervous system (CNS) injuries as the most common causes of death. Preclinical research is badly needed to produce a sound base for future clinical trials and possible improvements in clinical outcome. In our laboratory, we use piglets weighing approximately 25 kg. Ventricular fibrillation is produced by an AC current and left without treatment for 8-12 min, after which cardiopulmonary resuscitation according to current human guidelines is undertaken. The heart is then defibrillated and restoration of spontaneous circulation induced. During the procedure, blood pressure and flow measurements are obtained in the systemic, pulmonary, and cerebral circulation. Peroxidation and inflammation are monitored by systemic and cerebral venous plasma concentrations of isoprostane (8-iso-PGF(2alpha)), an indicator of oxidative damage, and prostaglandin F(2alpha) metabolite (15-keto-dihydro-PGF(2alpha)), an indicator of cyclooxygenase-2 activity, respectively. Neurocellular damage is monitored by the jugular plasma concentration of protein S-100beta. Neurological outcome is assessed at >24 h after the incident. Our results show that plasma concentrations of 8-iso-PGF(2alpha) are greater after more extended periods of ischemia. PBN (alpha-phenyl-N-tert-butyl nitrone), a so-called spin-trap scavenger, has a neuroprotective effect since neurological outcome is enhanced, and the 8-iso-PGF(2alpha) concentration is decreased during reperfusion. Use of water-soluble sulfonated PBN (S-PBN) results in better autoregulation of cerebral cortical blood flow and less peroxidation of CNS lipids during reperfusion. These observations suggest that our model can be used to explore neuroprotective effects of potential therapeutic agents.
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| 6. |
- Wiklund, Lars, et al.
(författare)
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Improved neuroprotective effect of methylene blue with hypothermia after porcine cardiac arrest
- 2013
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 57:8, s. 1073-1082
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundInduced mild hypothermia and administration of methylene blue (MB) have proved to have neuroprotective effects in cardiopulmonary resuscitation (CPR); however, induction of hypothermia takes time. We set out to determine if MB administered during CPR could add to the histologic neuroprotective effect of hypothermia.MethodsA piglet model of extended cardiac arrest (12 min of untreated cardiac arrest and 8 min of CPR) was used to assess possible additional neuroprotective effects of MB when administered during CPR before mild therapeutic hypothermia induced 30 min after restoration of spontaneous circulation (ROSC). Three groups were compared: C group (n = 8) received standard CPR; PH group (n = 8) received standard CPR but 30 min after ROSC these piglets were cooled to 34°C; the PH+MB group (n = 8) received an MB infusion 1 min after commencement of CPR and the same cooling protocol as the PH group. Three hours later, the animals were killed. Immediately after death, the brains were harvested pending histological and immunohistological analysis.ResultsCirculatory variables were similar in the groups except that cardiac output was greater in the PH+MB group 2–3 h after ROSC. Cerebral cortical neuronal injury and blood–brain barrier disruption was greatest in the C group and least in the MB group. The neuroprotective effect of MB and hypothermia was significantly greater than that of delayed hypothermia alone.ConclusionAdministration of MB during CPR added to the short term neuroprotective effects of induced mild hypothermia induced 30 min after ROSC.
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| 7. |
- Wiklund, Lars, et al.
(författare)
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Neuro- and cardioprotective effects of blockade of nitric oxide action by administration of methylene blue
- 2007
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Ingår i: Neuroprotective agents. - : Wiley. - 9781573316859 ; , s. 231-244
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Konferensbidrag (refereegranskat)abstract
- Methylene blue (MB), generic name methylthioninium (C16H18ClN3 S · 3H2O), is a blue dye synthesized in 1876 by Heinrich Caro for use as a textile dye and used in the laboratory and clinically since the 1890s, with well-known toxicity and pharmacokinetics. It has experimentally proven neuroprotective and cardioprotective effects in a porcine model of global ischemia–reperfusion in experimental cardiac arrest. This effect has been attributed to MB's blocking effect on nitric oxide synthase and guanylyl cyclase, the latter blocking the synthesis of the second messenger of nitric oxide. The physiological effects during reperfusion include stabilization of the systemic circulation without significantly increased total peripheral resistance, moderately increased cerebral cortical blood flow, a decrease of lipid peroxidation and inflammation, and less anoxic tissue injury in the brain and the heart. The last two effects are recorded as less increase in plasma concentrations of astroglial protein S-100β, as well as troponin I and creatine kinase isoenzyme MB, respectively.
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