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Biomedical subjects

T Juvonen

Publications and source records attributed to T Juvonen.

At least 19 recordsLinked to original sources
PubMed2003

Value of the Glasgow Aneurysm Score in predicting the immediate and long-term outcome after elective open repair of infrarenal abdominal aortic aneurysm.

BACKGROUND: This study aimed to explore the value of the Glasgow Aneurysm Score in predicting the immediate and long-term outcome after elective open repair of abdominal aortic aneurysm (AAA). METHODS: Some 403 patients underwent elective open repair of an infrarenal AAA and were classified retrospectively according to the criteria of the Glasgow Aneurysm Score (risk score = (age in years) + (7 for myocardial disease) + (10 for cerebrovascular disease) + (14 for renal disease)). RESULTS: Fourteen patients (3.5 per cent) died after operation, 23 (5.7 per cent) had a myocardial infarction and six (1.5 per cent) had a stroke. One hundred and nine patients (27.0 per cent) experienced severe postoperative complications. The Glasgow Aneurysm Score was predictive of postoperative death (area under the receiver-operator characteristic curve (AUC) 0.80, 95 per cent confidence interval (c.i.) 0.71 to 0.90), severe postoperative complications (AUC 0.67, 95 per cent c.i. 0.61 to 0.73), myocardial infarction (AUC 0.72, 95 per cent c.i. 0.62 to 0.82), myocardial infarction-related postoperative death (AUC 0.78, 95 per cent c.i. 0.63 to 0.94) and stroke (AUC 0.84, 95 per cent c.i. 0.74 to 0.95). Univariate analysis showed that this risk index was also predictive of long-term survival. CONCLUSION: The Glasgow Aneurysm Score is a good predictor of outcome after elective open repair of AAA. Its simplicity and accuracy make it useful for preoperative risk stratification.

Aged↗
PubMed2002

Increased amount of type III pN-collagen in AAA when compared with AOD.

OBJECTIVE: the extent of the processing of type III procollagen to type III collagen was determined in nine human abdominal aortic aneurysms (AAA), and compared with ten samples of aortoiliac occlusive disease (AOD). METHODS: the aminoterminal propeptide (PIIINP) and telopeptide (IIINTP) of type III procollagen and collagen, respectively, were immunologically measured in the soluble and insoluble fractions of the extracellular matrix. The assay for PIIINP in the insoluble matrix was further validated. RESULTS: the insoluble matrices of AAAs contained at least 12 times more incompletely processed type III pN-collagen than AOD specimens (0.74% and 0.061%, respectively). Also, the soluble extracts of AAAs tended to contain more non-processed type III pN-collagen than free, properly cleaved aminoterminal propeptide. CONCLUSIONS: the larger amount of type III pN-collagen suggests an alteration in the metabolism of type III collagen in AAAs. This may partially explain the decreased tensile strength of the aortic tissue.

Aged↗
PubMed2002

Accuracy of hand-held Doppler in planning the operation for primary varicose veins.

OBJECTIVE: To evaluate whether hand-held Doppler (HHD) examination is an adequate screening test in planning surgical treatment for primary varicose vein. DESIGN: Prospective study. MATERIALS: One hundred and eleven consecutive patients (142 legs) with primary, uncomplicated varicose veins. METHODS: Legs were examined clinically, with HHD and duplex ultrasonography on the same day at the outpatient clinic. The plan for the subsequent treatment was recorded separately after each examination. RESULTS: At the sapheno-femoral junction and at the sapheno-popliteal junction, the sensitivity was 56 and 23%, the specificity 97 and 96%, the positive predictive values was 98 and 43%, the negative predictive value was 44 and 91%, and the Kappa coefficient was 38 and 24%, respectively. Clinical examination failed to correctly plan the treatment in 21 (26%) of 80 proposed operations. In 13 limbs (9.1%) the HHD-based treatment plan was modified on the basis of duplex ultrasound findings. In seven cases, patients would have undergone only stab avulsion procedure, whereas stripping of a saphenous vein was indicated on the basis of duplex ultrasound findings. In two other cases, HHD findings would have led to resect the wrong saphenous vein. In six cases, the treatment was wrongly planned because of assessment problems during HHD examination at the popliteal fossa. CONCLUSIONS: The accuracy of HHD in the preoperative evaluation of primary, uncomplicated varicose veins is unsatisfactory. These results suggest that duplex ultrasonography should be considered as the preoperative diagnostic method of choice.

Adult↗
PubMed2002

Apoptotic activity is increased in brain cortex infarct after hypothermic circulatory arrest in a porcine model.

OBJECTIVE: It has been shown that apoptosis contributes to neuronal cell death after ischemia, and we evaluated the degree of apoptotic activity occurring in brain cortex of pigs after hypothermic circulatory arrest (HCA). DESIGN: Thirty-one pigs underwent 75 min of HCA at 20 degrees C. Histological examination of the brain was performed, and slides of brain cortex were evaluated for apoptotic activity by the TUNEL method. RESULTS: Ten animals died during the first postoperative day and 21 survived until the seventh postoperative day. Brain cortex infarcts were found in animals that survived 7 days and these were included in this study. The median histopathological score among animals that died on the first postoperative day was 3.0 (range, 2-4), whereas it was 4.0 (range, 2-4) among survivors (p = 0.019). The apoptotic index was particularly high in the area of the infarct, whereas only a few TUNEL-stained cells were observed in noninfarcted areas. The apoptotic index was nil in all pigs that died in the first postoperative period, whereas it was 2.0 (range, 0-6) among the animals that survived until the seventh postoperative day (p < 0.0001). CONCLUSION: The apoptotic index was significantly increased in brain cortex infarcts of animals that survived 7 days after HCA, whereas only a few apoptotic cells were observed in noninfarcted areas of these animals as well as in animals that died on the first postoperative day. Further studies are required to elucidate the timing of development of brain infarction after HCA and whether neuroprotective strategies targeting the apoptotic process may mitigate brain damage.

Animals↗
PubMed2002

Effects of diclofenac in the prevention of pericardial effusion after coronary artery bypass surgery. A prospective, randomized study.

BACKGROUND: It is suggested that pericardial effusions after cardiac surgery can be managed with non-steroid anti-inflammatory drugs, but the efficacy of this therapy is not well established. This study was planned to evaluate the efficacy of the prophylactic use of diclofenac in the prevention of pericardial effusion after coronary artery bypass surgery. METHODS: In a prospective, randomized study, diclofenac sodium 50 mg was administered orally every 8 hours to 22 patients in the postoperative period. The control group consisted of 19 patients who were not given postoperatively either steroids or non-steroid anti-inflammatory drugs. RESULTS: Twelve patients of the diclofenac-treated group (54.5%) and 7 of the control group (36.8%) experienced supraventricular arrhythmias postoperatively. There was no statistically significant difference in the size of postoperative pericardial effusion as well as in the occurrence of pleural effusion in both groups. However, there was a higher rate of significant pericardial effusion (grade I-III) in the control group as compared with the diclofenac-treated group (52.6% vs 31.8%, p=ns). Based on chest X-ray findings, patients in the control group had higher incidence of pleural effusion either alone (42.1% vs 22.7%, p=ns) or combined with pericardial effusion (21.0% vs 13.6%, p=ns). Patients who received diclofenac had lower median C-reactive protein concentration (76.0+/-45.2 mg/L) than the patients of the control group (99.6+/-47.8 mg/L), (p=ns). CONCLUSIONS: The results of the present study suggest that diclofenac, even if without a striking effect, may lessen the degree of inflammatory reaction after cardiac surgery and may be useful in the prevention and in the management of early pericardial effusion after cardiac surgery.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2001

Transmembrane carbonic anhydrase, MN/CA IX, is a potential biomarker for biliary tumours.

BACKGROUND/AIMS: Carbonic anhydrase isoenzyme IX (MN/CA IX) is a transmembrane protein with a suggested function in maintaining the acid-base balance and intercellular communication. Previous studies have demonstrated that MN/CA IX is expressed in the basolateral plasma membrane of normal biliary epithelial cells, but not in hepatocytes. This study was designed to examine the expression of MN/CA IX in hepatobiliary neoplasms and to elucidate its value as a marker for biliary differentiation. METHODS: Fifty-seven hepatobiliary lesions were immunostained for MN/CA IX using biotin-streptavidin complex method. Twenty samples containing normal biliary epithelium and five containing normal liver tissue were used as controls. RESULTS: In the biliary epithelial tumours, immunostaining for MN/CA IX was mainly localized at the basolateral surface of the epithelial cells, like in normal mucosa. All non-invasive dysplastic lesions and 57% of invasive lesions of gall-bladder expressed MN/CA IX. In liver, 78% of cholangiocellular malignant lesions showed a positive reaction for MN/CA IX, whereas only 33% of hepatocellular carcinomas showed a weak immunoreaction. CONCLUSIONS: Our results suggest that abnormal expression of MN/CA IX may be linked to malignant transformation of hepatobiliary cells. In addition, it seems to be a promising marker for biliary differentiation in hepatobiliary neoplasms.

Antigens, Neoplasm↗
PubMed2001

Determinants of mortality after hypothermic circulatory arrest in a chronic porcine model.

OBJECTIVE: Beside neurological morbidity, mortality is a relevant end-point of experimental porcine model of hypothermic circulatory arrest (HCA) and this study was conducted to identify the determinants for postoperative death. METHODS: One hundred and thirty-five pigs underwent a 75-min period of HCA at 20 degrees C to evaluate the efficacy of different methods of cerebral protection. RESULTS: Survival rate at 7-day follow-up was 52%. Lower oxygen extraction, oxygen consumption/kg, and venous lactate at the end of cooling and higher oxygen delivery rates were significantly associated with better outcome. Logistic regression showed that the oxygen consumption/kg at the end of cooling was the only predictor of mortality (P=0.046). Animals with an oxygen consumption/kg rate less than 1.43 ml/min per kg at the end of cooling had a mortality rate of 28%, whereas it was 50% among animals with an oxygen consumption/kg rate higher or equal to 1.43 ml/min per kg (P=0.020). The latter had even an increased 1-day mortality rate (40% vs. 26%) (P not significant). The mortality rate after anesthesia induction with ketamine plus 100% of oxygen was 38%, 45% after anesthesia induction with ketamine plus 35% oxygen, and 53% after anesthesia with medetomidine plus 35% oxygen (P not significant). CONCLUSIONS: Parameters of oxyhemodynamics should be monitored especially from the induction of anesthesia to the end of cooling before a 75-min period of HCA. The use of medetomidine and/or 35% of oxygen at induction of anesthesia should be avoided in favor of ketamine plus 100% of oxygen.

Anesthesia, General↗
PubMed2001

The N-methyl-D-aspartate antagonist memantine has no neuroprotective effect during hypothermic circulatory arrest: a study in the chronic porcine model.

BACKGROUND: Glutamate excitotoxicity has an important role in the development of brain injury after prolonged hypothermic circulatory arrest. The goal of the present study was to determine the potential efficacy of memantine, an N -methyl-D -aspartate receptor antagonist, to mitigate cerebral injury after hypothermic circulatory arrest. METHODS: Twenty pigs (23-33 kg) were randomly assigned to receive memantine (5 mg/kg) or placebo in a blinded fashion before a 75-minute period of hypothermic circulatory arrest at 20 degrees C. Hemodynamic, electroencephalographic, and metabolic monitoring were carried out. The intracerebral concentrations of glucose, lactate, glutamate, and glycerol were measured by means of enzymatic methods on a microdialysis analyzer. Daily behavioral assessment was performed until the animals died or were put to death on day 7. Histologic analysis of the brain was carried out in all animals. RESULTS: In the memantine group, 5 of 10 animals survived 7 days compared with 9 of 10 in the placebo group. The median behavioral score at day 7 was 3.5 in the memantine group and 7.5 in the placebo group (P >.2). Among the surviving animals, medians were 9.0 and 8.0 on day 7 (P >.2), respectively. The medians of recovered electroencephalographic bursts were equal in both groups. The median of total histopathologic score was 16 in the memantine group and 14 in the placebo group (P >.2). There was a negative correlation between glutamate levels and electroencephalographic burst recovery (tau = -0.377, P =.043). A positive correlation was found between the highest individual glutamate value and histopathologic score (tau = 0.336, P =.045). CONCLUSIONS: The present study demonstrates that memantine has no neuroprotective effect after hypothermic circulatory arrest in the pig. In addition, we have shown the accuracy of cerebral glutamate measurements to predict histopathologic injury after hypothermic ischemia.

Animals↗
PubMed2001

Use of doxycycline to decrease the growth rate of abdominal aortic aneurysms: a randomized, double-blind, placebo-controlled pilot study.

OBJECTIVE: Eradication of Chlamydia pneumoniae infection and inhibition of elastolytic matrix metalloproteinases with doxycycline have been suggested to reduce the growth rates of small abdominal aortic aneurysms (AAA). We designed a study to investigate the efficacy of doxycycline in reducing the expansion of small AAAs. SUBJECTS AND METHODS: This was a prospective, double-blind, randomized, placebo-controlled study that was set in a university referral hospital. The study group consisted of 32 of 34 initially eligible patients who had an AAA diameter perpendicular to the aortic axis of 30 mm or more in size or a ratio of infrarenal to suprarenal aortic diameter of 1.2 or more and a diameter less than 55 mm. Patients were randomly assigned to receive either doxycycline (150 mg daily) or placebo during a 3-month period and underwent ultrasound surveillance during an 18-month period. Outcome measures included aneurysm expansion rates, the number of patients who had AAA rupture or repair, C pneumoniae antibody titers, and serum concentrations of C-reactive protein. RESULTS: The aneurysm expansion rate in the doxycycline group was significantly lower than that in the placebo group during the 6- to 12-month (P = .01) and the 12- to 18-month periods (P =.01). Five patients (41%) in the placebo group and 1 patient (7%) in the doxycycline group had an overall expansion of the aneurysm of 5 mm or more during the 18-month follow-up. Among the placebo group patients, a higher expansion rate was observed in those with enhanced C pneumoniae immunoglobulin G antibody titers (> 128) than in those with lower titers (P = .03). Doxycycline treatment had no clear effect on antibody titers. However, at 6-month follow-up, C-reactive protein levels in the doxycycline group were significantly lower than the baseline levels (P = .01). CONCLUSIONS: The results of this small pilot study suggest that doxycycline may favorably alter the outcome of patients with small AAA. However, because of the small size of this randomized study and of the potentially confounding effect of pretreatment risk factors, doxycycline-based treatment cannot be justified only on the ground of the current results. Because of the high prevalence of this disorder and its clinical, social, and economic relevance, a multicenter study should be performed to further investigate whether there is any place for medical treatment of small AAAs.

Aged↗
PubMed2001

The role of cerebral microdialysis in predicting the outcome after experimental hypothermic circulatory arrest.

OBJECTIVE: To evaluate whether and which of the cerebral microdialysis parameters are predictive of postoperative outcome after an experimental 75-min period of hypothermic circulatory arrest (HCA) in a chronic porcine model. DESIGN: Seventy-four juvenile female pigs underwent a 75-min period of HCA at 20 degrees C. A microdialysis catheter was placed into the cortex gray matter and brain extracellular concentrations of glucose, lactate, glycerol and glutamate were measured throughout the experiment by enzymatic methods using a microdialysis analyzer. Surviving animals were sacrificed on the 7th postoperative day and histopathological examination of the brain was performed. RESULTS: Brain glucose concentrations were higher in animals that survived (p = 0.017), especially from the 90-min until the 7-h interval after the start of rewarming. The blood venous concentrations of glucose were also higher among survivors, and correlated significantly with the brain glucose levels at 2-h and 4-h intervals after the start of rewarming. Higher concentrations of brain lactate, glycerol and glutamate were observed throughout the study among animals that died postoperatively. Brain glutamate and glycerol concentrations were significantly, negatively correlated with brain glucose concentrations. The lactate/glucose ratio was significantly lower among survivors during the postoperative period (p=0.014). Furthermore, brain glucose concentrations were higher and brain glycerol concentrations lower among the animals that did not develop brain infarction, but such differences did not reach statistical significance. CONCLUSION: Cerebral microdialysis is a useful tool for cerebral monitoring during experimental HCA. Low brain glucose concentrations and high brain lactate/glucose ratios after HCA are strong predictors of postoperative death. Brain glucose concentrations are negatively correlated with brain glycerol and glutamate concentrations.

Animals↗
PubMed2001

Inhaled nitric oxide effectively decreases right heart afterload following right heart infarct in pigs.

OBJECTIVE: To test the hypothesis that nitric oxide is beneficial in acute right heart failure after right ventricle infarct. Right ventricle infarct results in a decrease in right heart function with a subsequent reduction in ejection fraction and cardiac index. The pulmonary circulation is compromised as the right ventricle weakens, and the resulting stasis and further weakening of the ventricle present clinically as an increase in right heart afterload. Pulmonary vasodilation should ease these hemodynamic symptoms of right heart infarct. DESIGN: Ten 3-4-month-old pigs were chosen as experimental animals. All animals were cannulated, a sternotomy was performed and branches of the right main coronary were ligated to cause infarct of the right ventricle. After a 4-h stabilization period, all animals received fluid preload with a dextrose-based solution after which control hemodynamic measurements were recorded. Treatment with inhaled nitric oxide was begun at progressive concentrations and hemodynamic measurements recorded at 30-min intervals. RESULTS: Nitric oxide treatment significantly reduced right heart afterload, which was also apparent as a reduction in left heart preload. A significant deterioration was observed in cardiac output as well as in left and right ventricle stroke work indices. CONCLUSION: The use of nitric oxide in this model of right heart infarct in previously healthy young swine effected a decrease in both right heart afterload and left heart preload, with an overall deterioration in global hemodynamics.

Administration, Inhalation↗
PubMed2000

Is maintained cranial hypothermia the only factor leading to improved outcome after retrograde cerebral perfusion? An experimental study with a chronic porcine model.

BACKGROUND: Previous studies have shown that retrograde cerebral perfusion can improve neurologic outcome after prolonged hypothermic circulatory arrest. Here we have compared two temperatures of retrograde cerebral perfusion (15 degrees C and 25 degrees C) with hypothermic circulatory arrest at systemic hypothermia of 25 degrees C to clarify whether the possible benefit of retrograde cerebral perfusion may only be due to improved cooling effect. METHODS: Eighteen pigs (23-27 kg) were randomly assigned to undergo 15 degrees C retrograde cerebral perfusion at systemic hypothermia of 25 degrees C, 25 degrees C retrograde cerebral perfusion at 25 degrees C systemic hypothermia, or hypothermic circulatory arrest at 25 degrees C for 40 minutes. Flow was adjusted to maintain superior vena cava pressure at 20 mm Hg during retrograde cerebral perfusion. Hemodynamic, electrophysiologic, metabolic, and temperature monitoring were performed until 4 hours after the start of rewarming. Daily behavioral assessment was done until death or until the animals were killed on day 7. Histopathologic analysis of the brain was carried out on all animals. RESULTS: Epidural temperatures were lower in the 15 degrees C retrograde cerebral perfusion group during the intervention (P <.05). In the 15 degrees C retrograde cerebral perfusion group, 4 (67%) of 6 animals survived for 7 days compared with 3 (50%) of 6 in both the 25 degrees C retrograde cerebral perfusion and hypothermic circulatory arrest groups. The median total histopathologic score was 5 in the 15 degrees C retrograde cerebral perfusion group and 7 in the 25 degrees C retrograde cerebral perfusion group (P =.04). CONCLUSIONS: These findings suggest that enhanced cranial hypothermia is the major beneficial factor of retrograde cerebral perfusion when careful attention is paid to its implementation.

Animals↗
PubMed2000

Lamotrigine improves cerebral outcome after hypothermic circulatory arrest: a study in a chronic porcine model.

BACKGROUND: Glutamate excitotoxicity has an important role in the development of brain injury after prolonged hypothermic circulatory arrest. The goal of the present studies was to determine the potential efficacy of lamotrigine, an Na(+) channel blocker, to mitigate cerebral injury after hypothermic circulatory arrest. METHODS: Sixteen pigs (21-27 kg) were randomly assigned to receive lamotrigine (20 mg/kg) or placebo in a blinded fashion before a 75-minute period of hypothermic circulatory arrest (20 degrees C). Hemodynamic, electroencephalographic, and metabolic monitoring were carried out. S-100beta protein was determined up to the first postoperative morning. Daily behavioral assessment was performed until the animal died or was put to death on day 7. Histologic analysis of the brain was carried out in all animals. RESULTS: Complete behavioral recovery was seen in 5 of 8 (63%) animals after lamotrigine administration, compared with 1 of 8 (13%) in the placebo group (P =.02). Among the animals that survived for 7 days, the median behavioral score was higher in the lamotrigine group (8 vs 7, P =.02). The medians of recovered electroencephalographic bursts in the lamotrigine group were higher than those in the placebo group 4 1/2 hours after the start of rewarming (P =.01). The median S-100beta level was lower in the lamotrigine group (0.01 microg/L) than in placebo controls (0.1 microg/L) 20 hours after the start of rewarming (P =.01). The median of total histopathologic score was 5.5 in the lamotrigine group and 7.5 in the placebo group (P =.06). CONCLUSIONS: The present data suggest that lamotrigine improves neurologic outcome after a prolonged period of hypothermic circulatory arrest.

Analysis of Variance↗
PubMed2000

Leukocyte filtration improves brain protection after a prolonged period of hypothermic circulatory arrest: A study in a chronic porcine model.

BACKGROUND: Ischemic cerebral injury follows a well-attested sequence of events, including 3 phases: depolarization, biochemical cascade, and reperfusion injury. Leukocyte infiltration and cytokine-mediated inflammatory reaction are known to play a pivotal role in the reperfusion phase. These events exacerbate the brain injury by impairing the normal microvascular perfusion and through the release of cytotoxic enzymes. The aim of the present study was to determine whether a leukocyte-depleting filter (LeukoGuard LG6, Pall Biomedical, Portsmouth, United Kingdom) could improve the cerebral outcome after hypothermic circulatory arrest. METHODS: Twenty pigs (23-30 kg) were randomly assigned to undergo cardiopulmonary bypass with or without a leukocyte-depleting filter before and after a 75-minute period of hypothermic circulatory arrest at 20 degrees C. Electroencephalographic recovery, S-100beta protein levels, and cytokine levels (interleukin 1beta, interleukin 8, and tumor necrosis factor alpha) were recorded up to the first postoperative day. Postoperatively, all animals were evaluated daily until death or until electively being put to death on day 7 by using a quantitative behavioral score. A postmortem histologic analysis of the brain was carried out on all animals. RESULTS: The rate of mortality was 2 of 10 in the leukocyte-depletion group and 5 of 10 in control animals. The risk for early death in control animals was 2.5 (95% confidence interval, 0.63-10.0) times higher than that of the leukocyte-depleted animals. The median behavioral score at day 7 was higher in the leukocyte-depletion group (8.5 vs 3.5; P =.04). The median of total histopathologic score was 8.5 in the leukocyte-depletion group and 15.5 in the control group (P =.005). CONCLUSION: A leukocyte-depleting filter improves brain protection after a prolonged period of hypothermic circulatory arrest.

Animals↗
PubMed2000

Intermittent retrograde cerebral perfusion during prolonged period of hypothermic circulatory arrest: a study in a chronic porcine model.

Previous studies have shown that although retrograde cerebral perfusion (RCP) improves cerebral outcome during hypothermic circulatory arrest (HCA), RCP exposes the brain to subsequent edema. In this study, we have compared intermittent RCP (I-RCP) with continuous RCP (C-RCP) and HCA alone to determine whether the rate of fluid sequestration can be decreased without losing the beneficial effects of RCP. Eighteen pigs were randomly assigned to undergo 75 min of I-RCP, C-RCP or HCA at 20 degrees C. Hemodynamic and metabolic measurements were carried out for upto 20 h. Behavioral assessments were examined until day 7, when histopathologic analysis of the brain was performed. The median amount of fluid sequestered was 145 ml after C-RCP and -50 ml after I-RCP (p = 0.04). The mean brain weight of the animals that died within the first postoperative day was significantly higher than that in electively sacrificed animals in the C-RCP group (p = 0.04). These data suggest that if RCP is implemented intermittently, the rate of cerebral edema can be decreased, without compromising the benefits of this strategy.

Animals↗