| 1. |
- Siikanen, Jonathan, et al.
(författare)
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An anesthetic method compatible with (18)F-FDG-PET studies in mice.
- 2015
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Ingår i: American journal of nuclear medicine and molecular imaging. - 2160-8407. ; 5:3, s. 270-277
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to establish an experimental setting and an anesthetic method compatible with future sequential studies using (18)F-FDG-PET single scans, i.e. autoradiographic measurements, for the estimation of metabolic rate of glucose (MRglc) in mice. In this study we had no access to a small animal PET scanner and therefore focus was on the anesthetic setting and optimization of the input function as a preparation for the future tumor metabolic studies. Initially, four combinations of intraperitoneal (ip) anesthesia were tested on tumor bearing mice. Fentanyl-fluanisone plus diazepam yielded low and stable blood glucose levels and kept the animals sedated for approximately 2 h. The anesthesia was also tested in a longitudinal (18)F-FDG study, where tumor bearing mice were anesthetized, injected with (18)F-FDG, and sampled for blood, before, one day after, and 8 days after treatment with cisplatin. The animals were in good condition during the entire study period. To validate the method, average MRglc of whole brain and cerebellum in mice were calculated and compared with the literature. The average MRglc in the whole brain and cerebellum were 46.2±4.4 and 39.0±3.1 µmol 100g(-1) min(-1). In the present study, we have shown that an ip anesthesia with a combination of fentanyl-fluanisone and diazepam is feasible and provides stable and low blood glucose levels after a fasting period of 4 h in experiments in nude mice with xenografted human tumors. We have also verified that (18)F-FDG, intraperitoneally administrated, results in an expected plasma activity uptake and clearance. The method doesn't alter the uptake in brain which is an indirect indication that the anesthesia doesn't alter the uptake in other organs. In combination with meticulous animal handling this set-up is reliable and future sequential tumor studies of early metabolic effects with calculation of MRglc following cytotoxic therapy are made possible.
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| 2. |
- Liuba, Petru, et al.
(författare)
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Coronary flow and reactivity, but not arrhythmia vulnerability, are affected by cardioplegia during cardiopulmonary bypass in piglets
- 2013
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Ingår i: Journal of Cardiothoracic Surgery. - : Springer Science and Business Media LLC. - 1749-8090. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Surgery under cardiopulmonary bypass (CPB) is still associated with significant cardiovascular morbidity in both pediatric and adult patients but the mechanisms are not fully understood. Abnormalities in coronary flow and function have been suggested to play an important role. Prior studies suggest protective effects on coronary and myocardial function by short intravenous (i.v.) infusion of cyclosporine A before CPB. Methods: Barrier-bred piglets (10-12 kg, n=20) underwent CPB for 45 min, with or without antegrade administration of cardioplegic solution. Prior to CPB, half of the animals in each group received an i.v. infusion of 100 mg/kg cyclosporine A. The left anterior descending coronary flow velocity responses to adenosine, serotonin, and atrial pacing, as well as left ventricular function and postsurgical vulnerability to atrial fibrillation (Afib) were assessed by intracoronary Doppler, epicardial echocardiography, and in vivo electrophysiological study, before and 8 hours after surgery. Plasma C-reactive protein (CRP) and fibrinogen were measured at both time-points. Results: Cyclosporine infusion did not influence any of the studied variables (p>0.4). Coronary peak flow velocity (cPFV) rose significantly after surgery especially in the cardioplegia group (p<0.01 vs. non-cardioplegia group and pre-surgery). cPFV responses to adenosine, but not to serotonin, tended to decrease (p=0.06) after surgery only in cardioplegia group (p=0.06; p=0.8 in non-cardioplegia group vs pre-surgery). Also, cPFV response to atrial pacing was lower in the cardioplegia than in the non-cardioplegia group (p=0.02). Neither vulnerability nor duration of induced Afib after CPB differed between groups (Chi-square p=0.4). Cyclosporine had no significant effect on coronary indexes or arrhythmia vulnerability (p>0.4). There was no difference in systolic myocardial function between groups at any time point. Conclusion: In piglets, CPB with cardioplegia was associated with profound abnormalities in coronary vasomotor tone and receptor-related flow regulation, whereas arrhythmia vulnerability appeared to be comparable with that in non-cardioplegia group. In this study, preconditioning with cyclosporine had no detectable protective effect on coronary circulation or arrhythmia vulnerability after CPB.
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| 3. |
- Forslid, Anders
(författare)
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Injektionsanestesi - tribromoetanol
- 2009
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Ingår i: Svensk Veterinärtidning. ; :Suppl 31, s. 35-36
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Roos, Åse, et al.
(författare)
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Protocol for Providing Additional Pseudo-Pregnant Recipient Mice for Embryo Transfer and Intra-Uterine Insemination by Plugging in the Middle of the Day
- 2008
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Ingår i: Scandinavian Journal of Laboratory Animal Science. - 0901-3393. ; 35:4, s. 305-310
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Tidskriftsartikel (refereegranskat)abstract
- The fact that 10% of female mice enter oestrus and allow mating in the middle of the day is an old observation that has been more or less forgotten. We here show that this old knowledge can be used to improve the efficacy of both embryo transfer and insemination protocols. The present technical paper shows that rapid re-arrangements of mating cages, to achieve pseudo-pregnant recipients in the middle of the day, can be of great advantage in emergency situations. Such emergency situations occur repeatedly, i.e. when a scientist has forgotten to re-arrange her/his mating cages, and the last important male suddenly has become ill and may die within a few hours. A rapid technique for uterine artificial insemination in mice in such situations is extremely valuable. An artificial intra-uterine insemination requires only a minimum of planning, a minimum of instrumentation and a minimum of surgical training. The artificial insemination must be performed shortly after mating due to rapid constriction of the utero-tubual junction (UTJ). This means that the timing of the insemination is very important. We here show that the success rate for embryo transfers, when using recipients plugged in the middle of the day, was the same as for ordinary overnight mating protocols. In addition, it: should be noted that the success rate (frequency of pregnancies) for uterine inseminations was 55% if using F1 recipients of C57BL/6J (considerable lower if using recipients of inbred C57BL/6J), which is amazingly high, since inseminations in mice is known to be tricky to perform in a reproducible manner.
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| 5. |
- Liuba, Petru, et al.
(författare)
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Effects of Bradykinin on Aortic Endothelial Function in ApoE-Knockout Mice With Chronic Chlamydia Pneumoniae Infection.
- 2007
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Ingår i: Circulation Journal. - : Japanese Circulation Society. - 1346-9843 .- 1347-4820. ; 71:9, s. 1480-1484
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Tidskriftsartikel (refereegranskat)abstract
- Background Impaired muscarinic receptor-mediated vasodilation is an important feature of early atherosclerosis. Earlier studies on apolipoprotein E-knockout mice (apoE-KO) mice suggested adverse effects of Chlamydia pneumoniae infection on the endothelial vasomotor responses of aortas to the muscarinic agonist methacholine. Using additional aorta samples the present study investigated the responses to bradykinin. Methods and Results ApoE-KO mice were repeatedly inoculated with either Chlamydia pneumoniae (C. pneumoniae) or saline. At 2, 6, and 10 weeks after the first inoculation, precontracted aorta rings from both groups were exposed to bradykinin in the absence and presence of L-NAME and diclofenac. In noninfected animals, the vasomotor responses to bradykinin were similar at all timepoints (p > 0.5). Compared with noninfected animals, the responses in infected animals tended to increase through the study period (p < 0.05 at 10 weeks). Although diclofenac and L-NAME had no effect in noninfected mice, they inhibited the responses to bradykinin in infected mice at 6 and, more markedly, 10 weeks (p < 0.05 for both). Conclusion Bradykinin stimulation of aorta endothelium from C. pneumoniae-infected apoE-KO animals appears to activate compensatory kinin receptor-related mechanisms that could involve nitric oxide and vasorelaxing prostanoids. Although the precise molecular mechanisms require further investigation, one could speculate that strategies increasing bradykinin availability might reverse the arterial dysfunction during chronic infectious disease.
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| 6. |
- Liuba, Petru, et al.
(författare)
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Protective effects of simvastatin on coronary artery function in swine with acute infection.
- 2006
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Ingår i: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 186:2, s. 331-336
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Tidskriftsartikel (refereegranskat)abstract
- Background: The risk for coronary events may rise during acute infection. Perturbation in coronary endothelial function emerges as one important link. We investigated whether simvastatin could protect the coronary arterial function from the adverse effects of acute infection in swine. Methods: Coronary endothelium-dependent and -independent vasomotor responses were assessed by Doppler velocimetry in 12 Chlamydia pneunioniae-infected and 6 sham-infected swine 2 weeks after intratracheal inoculation. Half of animals from the infection group were pretreated with simvastatin (80 mg daily), while the remaining animals received placebo. The treatment was started 2 weeks prior to inoculation and Continued until the end of the Study. ANOVA was used for statistical calculations. Data are mean +/- S.D. Results: All animals inoculated with C. pneumoniae developed IgM antibodies against this organism. As compared to noninfected animals, peak-to-baseline coronary flow velocity (CFV) ratio after bradykinin was significantly decreased in infected animals regardless of statin treatment (1,p=0.01). Intracoronary 10(-6) M acetylcholine caused slight dilatory responses in both noninfected and infected-treated animals (CFV ratio: 1.6 +/- 0.2and 1.4 +/- 0.2, respectively: p > 0.1),while a velocity drop (CFV ratio: 0.7 +/- 0.1; p < 0.01 versus noninfected-infected and treated). indicating constriction, was observed in in fected-non treated animals; 10(-5) M acetylcholine caused vasoconstriction in all animals, with a significantly more prolonged response in the infected-non treated group (p < 0.01). Intracoronary adenosine and SNP induced similar dilatory responses in all groups (p > 0.5). There were no differences in markers of systemic inflammation (fibrinogen, amyloid, and CRP) and lipid profile (HDL, LDL and total cholesterol) between the groups (p > 0.2). Conclusion: Acute infection is associated with impairment of the muscarinic and kinin-related reactivity of coronary circulation. These functional abnormalities are in part prevented by simvastatin through mechanisms unrelated to lipid lowering. (c) 2005 Elsevier Ireland Ltd. All rights reserved.
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| 7. |
- Liuba, Petru, et al.
(författare)
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Acute Chlamydia pneumoniae infection causes coronary endothelial dysfunction in pigs.
- 2003
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Ingår i: Atherosclerosis. - 1879-1484. ; 167:2, s. 215-222
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Tidskriftsartikel (refereegranskat)abstract
- Background: Coronary endothelial dysfunction contributes to the pathogenesis of acute coronary syndromes (ACSs). Acute Chlamydia pneumoniae infection has been epidemiologically associated with ACS. In this study, we investigated whether acute C. pneumoniae infection could alter the endothelial vasomotor function of porcine coronary vessels. Methods and results: Twenty pigs, 7–9 kg in weight, were inoculated intratracheally with C. pneumoniae (n=12) or saline (n=8), and investigated at 3 days (five infected/four non-infected) and 2 weeks (5+2 infected/four non-infected) after inoculation. The endothelium-dependent reactivity of coronary microcirculation was assessed at both time points by measuring peak coronary flow velocity (CFV) in response to bradykinin, before and after infusions with glutathione, an antioxidant, and Image-arginine, a substrate for nitric oxide synthase (NOS). CFV after bradykinin was significantly decreased in infected animals at both time points. At 2 weeks, both glutathione and Image-arginine significantly improved CFV after bradykinin. CFV after sodium nitroprusside (SNP) was similar in both groups. At 3 days, the relaxation responses of bradykinin-induced pre-contracted left anterior descending (LAD) coronary rings to bradykinin were significantly less in infected animals. NG-nitro-Image-arginine-methyl-ester, an NOS inhibitor, had significantly greater inhibitory effect on bradykinin-induced relaxation in infected animals. Plasma nitrate–nitrite and fibrinogen, and NOS activity from LAD coronary samples were significantly increased in infected animals. Conclusion: Acute C. pneumoniae infection causes endothelial dysfunction of both resistance and epicardial coronary vessels, and favours a pro-coagulant status. These effects could in part account for the epidemiologically suggested association between acute infection and ACS.
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| 8. |
- Liuba, Petru, et al.
(författare)
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Co-Infection with CHLAMYDIA PNEUMONIAE and HELICOBACTER PYLORI Results in Vascular Endothelial Dysfunction and Enhanced VCAM-1 Expression in ApoE-Knockout Mice.
- 2003
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Ingår i: Journal of Vascular Research. - : S. Karger AG. - 1423-0135 .- 1018-1172. ; 40:2, s. 115-122
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> Upregulation of proinflammatory endothelial cell adhesion molecules and decreased bioactivity of endothelial nitric oxide (NO) are important in the pathogenesis of atherosclerosis. We investigated the effects of co-infection with <i>Chlamydia pneumoniae</i> and <i>Helicobacter pylori </i>on these two events in apoE-KO mice. <i>Methods:</i> Thirty-two apoE-KO mice, 8 weeks old, were equally divided into 4 groups. The first 2 groups were infected with either <i>C. pneumoniae</i> or <i>H. pylori,</i> while the 3rd group was infected with both <i>C. pneumoniae</i> and <i>H. pylori</i>. Mice from the 4th group and 4 wild-type mice served as controls. Thoracic and abdominal aortas were harvested after 10 weeks, and staining for vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 was analyzed by immunocytochemistry. The endothelial vasomotor responses of thoracic aortas to methacholine were studied in organ chambers in the absence and presence of <i>L</i>-NAME. The plasma levels of nitrate/nitrite were measured. <i>Results:</i> Staining for VCAM-1 was more intense at the branching sites of aortas from mice with co-infection than in mono-infected or noninfected apoE-KO mice. The relaxation responses to methacholine and the plasma levels of nitrate/nitrite were significantly less in the co-infected group than in the other groups (p < 0.05). <i>Conclusion:</i> Co-infection of apoE-KO mice with <i>C. pneumoniae</i> and <i>H. pylori</i> seems to be associated with impaired bioactivity of endothelial NO and increased expression of VCAM-1 at branching sites. The findings may suggest an additive interaction of these pathogens in atherogenesis.
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| 9. |
- Martoft, L, et al.
(författare)
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CO2 induced acute respiratory acidosis and brain tissue intracellular pH: a P-31 NMR study in swine
- 2003
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Ingår i: Laboratory Animals. - : SAGE Publications. - 0023-6772 .- 1758-1117. ; 37:3, s. 241-248
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Tidskriftsartikel (refereegranskat)abstract
- High concentration carbon dioxide (CO2) is used to promote pre-slaughter anaesthesia in swine and poultry, as well as short-lasting surgical anaesthesia and euthanasia in laboratory animals. Questions related to animal welfare have been raised, as CO2 anaesthesia does not set in momentarily. Carbon dioxide promotes anaesthesia by lowering the intracellular pH in the brain cells, but the dynamics of the changes in response to a high concentration of CO2 is not known. Based on P-31 NMR spectroscopy, we describe CO2-induced changes in intracellular pH in the brains of five pigs inhaling 90% CO2 in ambient air for a period of 60 s, and compare the results to changes in arterial blood pH, P-CO2, O-2 saturation and HCO(3)(-)concentration. The intracellular pH paralleled the arterial pH and P-CO2 during inhalation of CO2; and it is suggested that the acute reaction to CO2 inhalation mainly reflects respiratory acidosis, and not metabolic regulation as for example transmembrane fluxes of H+/HCO3-. The intracellular pH decreased to approximately 6.7 within the 60 s inhalation period, and the situation was metabolically reversible after the end of CO2 inhalation. The fast decrease in intracellular pH supports the conclusion that high concentration CO2 leads to anaesthesia soon after the start of inhalation.
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| 10. |
- Martoft, L, et al.
(författare)
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Effects of CO2 anaesthesia on central nervous system activity in swine
- 2002
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Ingår i: Laboratory Animals. - 0023-6772. ; 36:2, s. 115-126
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to examine the changes in central nervous system (CNS) activity and physical behaviour during induction and awakening from CO2 anaesthesia. Two studies, each using pigs immersed into 90% CO2 gas for a period of 60s were performed. In study 1, we monitored middle latency auditory evoked potentials (changes in latencies, amplitudes and a depth of anaesthesia index), electroencephalographic parameters (delta, theta, alpha and beta electroencephalographic power and 95% spectral edge frequency) and heart rate; and in study 2, we monitored body movements and arterial and venous partial pressure of CO2 and O-2. No behavioural signs of distress were observed during the early part of the induction. The swine exhibited muscular activity from 13-30s after induction-start as well as during awakening from anaesthesia, possibly because of a transitory weaker suppression of the brain stem than of the cortex. The CNS and blood gas parameters started to change from the very start of induction. The CNS suppression lasted only approximately one minute after the end of the induction period. The two studies indicated a good temporal relationship between changes in amplitude, depth of anaesthesia index, spectral edge frequency, and arterial P-CO2 during the induction period.
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