Publications by authors named "Jorma Hirvonen"
Background: Because of current limitations in improving metabolic support to the brain during hypothermic circulatory arrest (HCA), attenuation of ischemia-reperfusion injury remains an area of therapeutic intervention of relevance. Apotransferrin (Apo-Tf), alpha 1-acid glycoprotein (AGP), and C1-esterase inhibitor (C1-INH) have been herein evaluated as potential beneficial agents in reducing the ischemia-reperfusion injury in a surviving model of HCA.
Methods: Apo-Tf 100 mg/kg (n = 6), C1-INH 50 IU/kg (n = 6), AGP 100 mg/kg (n = 6), or NaCl 0.
Background: The superiority of the pH-stat to the alpha-stat acid-base strategy during cardiopulmonary bypass as a neuroprotective method during hypothermic circulatory arrest is still controversial. In the present study, brain metabolism and outcome have been evaluated in a surviving model of experimental hypothermic circulatory arrest.
Methods: Twenty pigs undergoing 75-minutes of hypothermic circulatory arrest at a brain temperature of 18 degrees C were randomly assigned to the alpha-stat (n = 10) or pH-stat (n = 10) strategy during cardiopulmonary bypass.
Objective: To evaluate whether electroencephalography (EEG) recovery could be considered a reliable marker of brain injury after experimental hypothermic circulatory arrest (HCA).
Design: Cortical electrical activity was registered before and after a 75-min period of HCA in 27 pigs that survived 7 days after the experiment. The sum of EEG bursts was counted as a percentage of the sum of artifact-free bursts and suppressions, and this percentage was used as a measure of EEG activity in the analysis.
Background: The aim of this study was to evaluate the potential neuroprotective effect of topical head cooling during the first 2 postoperative hours after experimental hypothermic circulatory arrest.
Methods: Twenty pigs underwent a 75-minute period of hypothermic circulatory arrest and were randomly assigned to rewarming to 37 degrees C or to undergo topical cooling of the head for 2 hours from the start of rewarming followed by a period of external rewarming to 37 degrees C.
Results: The 7-day survival rate was 70% in the control group and 60% in the topical head cooling group.
Fructose-1,6-bisphosphate for improved outcome after hypothermic circulatory arrest in pigs.
J Thorac Cardiovasc Surg
March 2003
Objective: Fructose-1,6-bisphosphate is a high-energy intermediate in the anaerobic metabolism. It enhances glycolysis, preserves cellular adenosine triphosphate, and prevents the increase of intracellular calcium during ischemia. The potential neuroprotective effect of fructose-1,6-bisphosphate during hypothermic circulatory arrest was evaluated in a surviving porcine model.
View Article and Find Full Text PDFObjectives: The study was a follow-up one, in which blood pressure and hormonal changes were investigated during one winter swimming season in winter swimmers (WSs) and non-swimmer controls on three occasions (autumn, winter and spring). Humoral results were compared to psychological traits recorded at the time of the three blood samplings.
Results: Mean systolic blood pressure of the WSs fell from 134 +/- 12 mmHg to 128 +/- 12 mmHg (p < 0.
Objective: An increase in intracranial pressure has been shown to threaten the outcome of patients with ischemic or traumatic brain injury. Its impact on the outcome of pigs undergoing hypothermic circulatory arrest has been evaluated in this study.
Design: Fifty-six pigs underwent a 75-min period of hypothermic circulatory arrest at 20 degrees C.
Objective: Recent studies have shown that erythropoietin protects neurons from glutamate toxicity and ischemia. This study was performed to evaluate the potential neuroprotective effect of erythropoietin during experimental hypothermic circulatory arrest.
Methods: Twenty pigs were randomized to receive intravenously either 500 IU/kg recombinant human erythropoietin or saline before a 75-minute period of hypothermic circulatory arrest at an intracerebral temperature of 18 degrees C.
Neurotic psychopathology and alexithymia among winter swimmers and controls--a prospective study.
Int J Circumpolar Health
May 2002
Random samples of 25 voluntary Finnish winter swimmers (7 males, 18 females) and 11 controls (3 males, 8 females were followed prospectively during the winter season from October 1999 to May 2000 to (determine whether winter swimming is beneficial for mental well-being, as many of its practitioners claim. The Crown-Crisp Experimental Index (CCEI) was used for measuring free-floating anxiety, phobic anxiety, obsessionality, depression, somatic anxiety and hysteria, and the 20-item version of the Toronto Alexithymia Scale (TAS-20) for measuring alexithymia. Self-reported somatic and mental health and the reasons for and the frequency of winter-swimming were asked, too.
View Article and Find Full Text PDFObjectives: We sought to evaluate the potential efficacy of prolonged mild hypothermia after hypothermic circulatory arrest.
Methods: Twenty pigs, after a 75-minute period of hypothermic circulatory arrest, were randomly assigned to be rewarmed to 37 degrees C (normothermia group) or to 32 degrees C and kept at that temperature for 14 hours from the start of rewarming (hypothermia group).
Results: The 7-day survival was 30% in the hypothermia group and 70% in the normothermia group (P =.
Background: Lamotrigine and leukocyte filtration seem to improve cerebral protection during experimental hypothermic circulatory arrest (HCA). This study was performed to evaluate whether their combined use may further improve cerebral protection.
Methods: Twenty-four pigs undergoing 75-minute period of HCA at 20 degrees C were randomly assigned to receive saline; lamotrigine (20 mg/kg) before HCA (L); or lamotrigine (20 mg/kg) before HCA plus leukocyte filtration before and after HCA (L + LF).